Make it possible to specify the HEAD for the internal findUpstreamBranchPoint function.
Make it possible to specify the HEAD for the internal findUpstreamBranchPoint function.

This isn't used right now in git-p4 but I use it in an external script that loads git-p4 as module.

Signed-off-by: Simon Hausmann <557de780ea7e35794f4cd12cd1c79efe52f1d714@trolltech.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git