Pointer cleanup (#242)

- Made greater use of smart pointers, eliminating many instances of manual memory management
- Do not use pointers at all for many non-polymorphic classes
- Assorted other code cleanup

model/FrameRect.h

@@ -35,16 +35,16 @@ namespace glabels
 			Q_DECLARE_TR_FUNCTIONS(FrameRect)
 
 		public:
-			FrameRect( const Distance& w,
-			           const Distance& h,
-			           const Distance& r,
-			           const Distance& xWaste,
-			           const Distance& yWaste,
-			           const QString&  id = "0" );
+			FrameRect( Distance       w,
+			           Distance       h,
+			           Distance       r,
+			           Distance       xWaste,
+			           Distance       yWaste,
+			           const QString& id = "0" );
 
 			FrameRect( const FrameRect& other ) = default;
 
-			Frame* dup() const override;
+			std::unique_ptr<Frame> clone() const override;
 
 			Distance r() const;
 			Distance xWaste() const;
@@ -53,14 +53,16 @@ namespace glabels
 			Distance w() const override;
 			Distance h() const override;
 
-			QString sizeDescription( const Units& units ) const override;
+			QString sizeDescription( Units units ) const override;
 
-			bool isSimilarTo( Frame* other ) const override;
+			bool isSimilarTo( const Frame& other ) const override;
 
 			const QPainterPath& path() const override;
 			const QPainterPath& clipPath() const override;
-			QPainterPath marginPath( const Distance& xSize,
-			                         const Distance& ySize ) const override;
+			QPainterPath marginPath( Distance xSize, Distance ySize ) const override;
+
+			// Debugging support
+			void print( QDebug& dbg ) const override;
 
 
 		private:
@@ -79,8 +81,4 @@ namespace glabels
 }
 
 
-// Debugging support
-QDebug operator<<( QDebug dbg, const glabels::model::FrameRect& frame );
-
-
 #endif // model_FrameRect_h