Clang: Add revision and completion management

Reparsing a document is expensive so we should avoid it by all means. In
this patch we prevent that the same document is send again. It isn't send
too in advance of a code completion if there was no changes before the
the completion position.

Change-Id: I0bb786ba1d4e7ce08611a518cb32f8cf8f4d0037
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/plugins/clangcodemodel/clangmodelmanagersupport.h

@@ -67,7 +67,9 @@ private:
     void onEditorOpened(Core::IEditor *editor);
     void onCurrentEditorChanged(Core::IEditor *newCurrent);
     void onCppDocumentReloadFinishedOnTranslationUnit(bool success);
-    void onCppDocumentContentsChangedOnTranslationUnit();
+    void onCppDocumentContentsChangedOnTranslationUnit(int position,
+                                                       int charsRemoved,
+                                                       int charsAdded);
     void onCppDocumentReloadFinishedOnUnsavedFile(bool success);
     void onCppDocumentContentsChangedOnUnsavedFile();