GitLab

* Stop loading git plugin
* Update completion and git-prompt to v2.10
* Update completion to v2.14

Certain themes need the 'clean' mark, and some people like to have the
'dirty' one, just like the original git_promp_info().

We probably shouldn't be modifying that function, there's no other clean
way to achieve our own status information, so let's try to emulate the
original as much as possible.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>

Using the upstream git completion and prompt stuff.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>