Revert "Code model: Update on changes from the versioning system."

This reverts commit 7aa2411693.
It breaks the code model updates completely. So reverting this change
until we have the right thing.

Reviewed-by: Roberto Raggi

src/plugins/cpptools/cppmodelmanagerinterface.h

@@ -102,12 +102,6 @@ public:
     virtual void renameUsages(CPlusPlus::Symbol *symbol) = 0;
     virtual void findUsages(CPlusPlus::Symbol *symbol) = 0;
 
-    virtual bool isIndexing() const = 0;
-
-signals:
-    void indexingStarted();
-    void indexingFinished();
-
 public Q_SLOTS:
     void updateModifiedSourceFiles();
     virtual void updateSourceFiles(const QStringList &sourceFiles) = 0;