Debugger engine types: Add note about keeping compatibility

Change-Id: I8f5723d53fcfb454eca8abf55a0720f12b0423d0
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>
Squish: Test more templates

Change-Id: Ia9d5afc621b4e79417f6aa1b64b6b9d9f7b5f38a
Reviewed-by: Christian Stenger <christian.stenger@digia.com>
Version bump

Change-Id: If2233d241e83f82400e4e910e405eabebf887d58
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>