Git: Support change links on commit editor

Useful for commit messages with "reverts <hash>" for example.

Can later be extended for interactive rebase

Change-Id: Ibf77433ecddfacbd8d443636ddbc406bda474aa7
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/vcsbase/vcsbaseeditor.h

@@ -103,6 +103,7 @@ protected:
     void setDiffFilePattern(const QRegExp &pattern);
     // Pattern for log entry. hash/revision number must be in the first capture group
     void setLogEntryPattern(const QRegExp &pattern);
+    virtual bool supportChangeLinks() const;
 
 public:
     virtual void init();