af-magic: add hg prompt and tweak virtualenv info (#8056)
af-magic: add hg prompt and tweak virtualenv info (#8056)

- Add mercurial support to af-magic, so now the vcs prompt will show up in either a git or hg repository
- The virtualenv prompt was white and bumped up against the user@hostname output
- Fixed that so its green (which I thought highlighted it more thematically) and has a space before user@hostname
tekniklr/oh-my-zsh,tekniklr/oh-my-zsh