Please consider add a new Git consistent color scheme

Hi,
  I'm glad to see this bash-git-prompt project is being actively maintained and continue to deliver values.

  However, I'd like to have color scheme which is consistent w/ the one used by Git. That is:
 
1. show number of untracked, conflicted and modified files in red
2. show number of staged files in green

Since user not only uses the number indicated by the prompt but also need drill down to the specific files, if base-git-prompt display default color scheme uses different color than the Git built-in, it confuses user.

This PR is intended to implement this idea in the additional "Solarized_Git" theme.
There is no need to include the ruby file, as this is just the current homebrew formula. It is not needed by the gitprompt itself.