Git: Silence rev-list execution

It's plumbing. Not interesting for the user.

Change-Id: I65bb7849c64f32ac24684715290acf26441c5d2b
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Git: Factorize ctor of Push to Gerrit

Change-Id: Ib668d0e29bac25bc2f78d8885b4dfa89c292b489
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Git: Rename branch -> targetBranch in Push to Gerrit

Change-Id: I725a7e9ece2bf1e8854dc077cb93a1f7cc1eb90c
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Git: Enable local branch selection in Push to Gerrit

Show dialog even if there are no local commits in current branch

Change-Id: I11e0c6505981712df51bb33694a6cba9704d7324
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>