Big-Ugly Style Update (#278)

* Bulk replaced tabs with spaces
* Bulk removed trailing whitespace from lines
* Replaced c-style comments with c++-style comments in file banners
* Replace nested namespace definitions with single concise definitions (C++17), this keeps the indentation more manageable
* Cleanup ordering and spacing of include directives
* Bulk renaming of header file extensions from '.h' to '.hpp'.
* Update CODING-STYLE.md
* Update target_compile_features from cxx_std_11 to cxx_std_20.
* Refresh .clang-format file.  Still needs a lot of tweaking.

.clang-format

@@ -1,28 +1,72 @@
 ---
 Language:        Cpp
-# BasedOnStyle:  Google
 AccessModifierOffset: -8
 AlignAfterOpenBracket: Align
-AlignConsecutiveAssignments: true
-AlignConsecutiveDeclarations: true
-AlignEscapedNewlinesLeft: true
-AlignOperands:   true
-AlignTrailingComments: true
+AlignArrayOfStructures: None
+AlignConsecutiveAssignments:
+  Enabled:         true
+  AcrossEmptyLines: false
+  AcrossComments:  false
+  AlignCompound:   false
+  AlignFunctionPointers: false
+  PadOperators:    true
+AlignConsecutiveBitFields:
+  Enabled:         false
+  AcrossEmptyLines: false
+  AcrossComments:  false
+  AlignCompound:   false
+  AlignFunctionPointers: false
+  PadOperators:    false
+AlignConsecutiveDeclarations:
+  Enabled:         true
+  AcrossEmptyLines: false
+  AcrossComments:  false
+  AlignCompound:   false
+  AlignFunctionPointers: false
+  PadOperators:    true
+AlignConsecutiveMacros:
+  Enabled:         false
+  AcrossEmptyLines: false
+  AcrossComments:  false
+  AlignCompound:   false
+  AlignFunctionPointers: false
+  PadOperators:    false
+AlignConsecutiveShortCaseStatements:
+  Enabled:         false
+  AcrossEmptyLines: false
+  AcrossComments:  false
+  AlignCaseColons: false
+AlignEscapedNewlines: Left
+AlignOperands:   Align
+AlignTrailingComments:
+  Kind:            Always
+  OverEmptyLines:  0
+AllowAllArgumentsOnNextLine: true
 AllowAllParametersOfDeclarationOnNextLine: true
-AllowShortBlocksOnASingleLine: false
+AllowBreakBeforeNoexceptSpecifier: Never
+AllowShortBlocksOnASingleLine: Never
 AllowShortCaseLabelsOnASingleLine: false
+AllowShortCompoundRequirementOnASingleLine: true
+AllowShortEnumsOnASingleLine: true
 AllowShortFunctionsOnASingleLine: Inline
-AllowShortIfStatementsOnASingleLine: false
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLambdasOnASingleLine: All
 AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
 AlwaysBreakAfterReturnType: None
 AlwaysBreakBeforeMultilineStrings: false
-AlwaysBreakTemplateDeclarations: true
+AlwaysBreakTemplateDeclarations: Yes
+AttributeMacros:
+  - __capability
 BinPackArguments: false
 BinPackParameters: false
-BraceWrapping:   
+BitFieldColonSpacing: Both
+BraceWrapping:
+  AfterCaseLabel:  false
   AfterClass:      true
-  AfterControlStatement: true
+  AfterControlStatement: Always
   AfterEnum:       true
+  AfterExternBlock: false
   AfterFunction:   true
   AfterNamespace:  true
   AfterObjCDeclaration: true
@@ -30,62 +74,176 @@ BraceWrapping:
   AfterUnion:      true
   BeforeCatch:     true
   BeforeElse:      true
+  BeforeLambdaBody: false
+  BeforeWhile:     false
   IndentBraces:    false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakAdjacentStringLiterals: true
+BreakAfterAttributes: Leave
+BreakAfterJavaFieldAnnotations: false
+BreakArrays:     true
 BreakBeforeBinaryOperators: None
+BreakBeforeConceptDeclarations: Always
 BreakBeforeBraces: Custom
+BreakBeforeInlineASMColon: OnlyMultiline
 BreakBeforeTernaryOperators: true
-BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeColon
+BreakInheritanceList: BeforeColon
+BreakStringLiterals: true
 ColumnLimit:     110
 CommentPragmas:  '^ IWYU pragma:'
-ConstructorInitializerAllOnOneLineOrOnePerLine: true
+CompactNamespaces: false
 ConstructorInitializerIndentWidth: 8
 ContinuationIndentWidth: 8
 Cpp11BracedListStyle: true
 DerivePointerAlignment: true
 DisableFormat:   false
+EmptyLineAfterAccessModifier: Never
+EmptyLineBeforeAccessModifier: LogicalBlock
 ExperimentalAutoDetectBinPacking: false
-ForEachMacros:   [ foreach, Q_FOREACH, BOOST_FOREACH ]
-IncludeCategories: 
+FixNamespaceComments: false
+ForEachMacros:
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IfMacros:
+  - KJ_IF_MAYBE
+IncludeBlocks:   Preserve
+IncludeCategories:
   - Regex:           '^"[A-Z].*\.h'
     Priority:        1
+    SortPriority:    0
+    CaseSensitive:   false
   - Regex:           '^<Q[A-Za-z]*\>'
     Priority:        2
+    SortPriority:    0
+    CaseSensitive:   false
   - Regex:           '^<[a-z]*>'
     Priority:        3
+    SortPriority:    0
+    CaseSensitive:   false
   - Regex:           '.*'
     Priority:        4
+    SortPriority:    0
+    CaseSensitive:   false
+IncludeIsMainRegex: '(Test)?$'
+IncludeIsMainSourceRegex: ''
+IndentAccessModifiers: false
+IndentCaseBlocks: false
 IndentCaseLabels: false
+IndentExternBlock: AfterExternBlock
+IndentGotoLabels: true
+IndentPPDirectives: None
+IndentRequiresClause: true
 IndentWidth:     8
 IndentWrappedFunctionNames: false
+InsertBraces:    false
+InsertNewlineAtEOF: false
+InsertTrailingCommas: None
+IntegerLiteralSeparator:
+  Binary:          0
+  BinaryMinDigits: 0
+  Decimal:         0
+  DecimalMinDigits: 0
+  Hex:             0
+  HexMinDigits:    0
+JavaScriptQuotes: Leave
+JavaScriptWrapImports: true
 KeepEmptyLinesAtTheStartOfBlocks: true
+KeepEmptyLinesAtEOF: false
+LambdaBodyIndentation: Signature
+LineEnding:      DeriveLF
 MacroBlockBegin: ''
 MacroBlockEnd:   ''
 MaxEmptyLinesToKeep: 2
 NamespaceIndentation: All
+ObjCBinPackProtocolList: Auto
 ObjCBlockIndentWidth: 2
+ObjCBreakBeforeNestedBlockParam: true
 ObjCSpaceAfterProperty: false
 ObjCSpaceBeforeProtocolList: false
+PackConstructorInitializers: NextLine
+PenaltyBreakAssignment: 2
 PenaltyBreakBeforeFirstCallParameter: 1
 PenaltyBreakComment: 300
 PenaltyBreakFirstLessLess: 120
+PenaltyBreakOpenParenthesis: 0
+PenaltyBreakScopeResolution: 500
 PenaltyBreakString: 1000
+PenaltyBreakTemplateDeclaration: 10
 PenaltyExcessCharacter: 1000000
+PenaltyIndentedWhitespace: 0
 PenaltyReturnTypeOnItsOwnLine: 200
 PointerAlignment: Left
+PPIndentWidth:   -1
+QualifierAlignment: Leave
+ReferenceAlignment: Pointer
 ReflowComments:  true
-SortIncludes:    true
+RemoveBracesLLVM: false
+RemoveParentheses: Leave
+RemoveSemicolon: false
+RequiresClausePosition: OwnLine
+RequiresExpressionIndentation: OuterScope
+SeparateDefinitionBlocks: Leave
+ShortNamespaceLines: 1
+SkipMacroDefinitionBody: false
+SortIncludes:    CaseSensitive
+SortJavaStaticImport: Before
+SortUsingDeclarations: LexicographicNumeric
 SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: true
+SpaceAroundPointerQualifiers: Default
 SpaceBeforeAssignmentOperators: true
+SpaceBeforeCaseColon: false
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeJsonColon: false
 SpaceBeforeParens: ControlStatements
-SpaceInEmptyParentheses: false
+SpaceBeforeParensOptions:
+  AfterControlStatements: true
+  AfterForeachMacros: true
+  AfterFunctionDefinitionName: false
+  AfterFunctionDeclarationName: false
+  AfterIfMacros:   true
+  AfterOverloadedOperator: false
+  AfterPlacementOperator: true
+  AfterRequiresInClause: false
+  AfterRequiresInExpression: false
+  BeforeNonEmptyParentheses: false
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceBeforeSquareBrackets: false
+SpaceInEmptyBlock: false
 SpacesBeforeTrailingComments: 1
-SpacesInAngles:  false
+SpacesInAngles:  Never
 SpacesInContainerLiterals: true
-SpacesInCStyleCastParentheses: false
-SpacesInParentheses: true
+SpacesInLineCommentPrefix:
+  Minimum:         1
+  Maximum:         -1
+SpacesInParens:  Custom
+SpacesInParensOptions:
+  InCStyleCasts:   false
+  InConditionalStatements: true
+  InEmptyParentheses: false
+  Other:           true
 SpacesInSquareBrackets: false
-Standard:        Cpp11
+Standard:        c++20
+StatementAttributeLikeMacros:
+  - Q_EMIT
+StatementMacros:
+  - Q_UNUSED
+  - QT_REQUIRE_VERSION
 TabWidth:        8
-UseTab:          ForIndentation
+UseTab:          Never
+VerilogBreakBetweenInstancePorts: true
+WhitespaceSensitiveMacros:
+  - BOOST_PP_STRINGIZE
+  - CF_SWIFT_NAME
+  - NS_SWIFT_NAME
+  - PP_STRINGIZE
+  - STRINGIZE
 ...