Code model: Update on changes from the versioning system.

Add changed signals to IVersionControl and
VCSManager and wire them to the update methods. Add a menu action for
manually updating. Improved version of reverted
7aa2411693.

Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>

src/plugins/coreplugin/iversioncontrol.h

@@ -106,6 +106,10 @@ public:
      */
     virtual bool vcsDelete(const QString &filename) = 0;
 
+signals:
+    void repositoryChanged(const QString &repository);
+    void filesChanged(const QStringList &files);
+
     // TODO: ADD A WAY TO DETECT WHETHER A FILE IS MANAGED, e.g
     // virtual bool sccManaged(const QString &filename) = 0;
 };