Git: Fix object leaks

Change-Id: I0efb368782ffb66cf6b8d39650fe7840c5ef2501
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Git: Provide highlighter for interactive rebase

Inspired by Vim highlighting

Change-Id: I1c967d22d26f313b5b7d37634713071d621f6f46
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>