Refactoring changes: Cleanup and improvements.

Previously RefactoringFiles were usually passed around by value.
However, since a RefactoringFile may sometimes own a QTextDocument
(when it was read from a file), that's not great and caused the
file to be reread after every copy.

With this change RefactoringFile becomes noncopyable and is always
owned by a shared pointer.

This change also allowed having const RefactoringFiles which is
useful because they can be safely used from other threads. See
CppRefactoringChanges::fileNoEditor.

Change-Id: I9045921d6d0f6349f9558ff2a3d8317ea172193b
Reviewed-on: http://codereview.qt.nokia.com/3084
Reviewed-by: Leandro T. C. Melo <leandro.melo@nokia.com>

src/plugins/cpptools/insertionpointlocator.h

@@ -39,11 +39,10 @@
 #include <CPlusPlusForwardDeclarations.h>
 
 #include <cplusplus/CppDocument.h>
+#include <cpptools/cpprefactoringchanges.h>
 
 namespace CppTools {
 
-class CppRefactoringChanges;
-
 class CPPTOOLS_EXPORT InsertionLocation
 {
 public:
@@ -100,7 +99,7 @@ public:
     };
 
 public:
-    InsertionPointLocator(CppRefactoringChanges *refactoringChanges);
+    InsertionPointLocator(const CppRefactoringChanges &refactoringChanges);
 
     InsertionLocation methodDeclarationInClass(const QString &fileName,
                                                const CPlusPlus::Class *clazz,
@@ -109,7 +108,7 @@ public:
     QList<InsertionLocation> methodDefinition(CPlusPlus::Declaration *declaration) const;
 
 private:
-    CppRefactoringChanges *m_refactoringChanges;
+    CppRefactoringChanges m_refactoringChanges;
 };
 
 } // namespace CppTools