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/Category.cpp

@@ -27,7 +27,8 @@ namespace glabels
 	{
 
 		Category::Category( const QString &id, const QString &name )
-			: mId(id), mName(name)
+			: mId(id),
+			  mName(name)
 		{
 			// empty
 		}