Git: Use commit encoding for git show.

At least for the Side-By-Side Diff for now.

Task-number: QTCREATORBUG-11115

Change-Id: Ic7cb91f48ca810a99c39b2d00acc0cf227d051be
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Git: Open untracked files on double-click

Task-number: QTCREATORBUG-6612
Change-Id: Ic56f4cd20063c9d4d05316607636aa3df1d1a5a3
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>