CppEditor: Fix Qt4 compile

Change-Id: I3bad3687e06a5333359bd926cae2493f709aeff2
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Vcs: Add variables containing the Vcs name (Git, etc.) and topic

This allows to have the git branch names (or tags, etc.) in the
build path or to pass that information to scripts.

Task-number: QTCREATORBUG-10376
Change-Id: I151990bdc7b85abbb427b2afae220adb4e918f4f
Reviewed-by: Eike Ziller <eike.ziller@digia.com>