Added new colour for the git segment when all changes have been added to...

... the staging area.

Did this for myself, maybe you or someone else would find it useful.

![screenshot from 2014-09-13 01 57 39](https://cloud.githubusercontent.com/assets/2438809/4258761/3bb5b49c-3ad9-11e4-8bb8-9490b6ea8573.png)