Fixed missing retcode function
Update the character used in powerline

The code points have been updated in 53fbfe1, see
- https://github.com/Lokaltog/powerline/commit/53fbfe15fead8cc7598bcb4ee9714a221ab7e446
- https://github.com/Lokaltog/powerline/issues/4
Update bundler.plugin.zsh

Added berks, foodcritic, kitchen, and knife commands to bundler plugin.
Update bundler.plugin.zsh

Added strainer & tailor to commands in bundler plugin.
Fixed slow behavior when using GitHub wrappers
Do not clear tab when calling it with an argument.
Merge pull request #1756 from rkj/master

Fixed missing retcode if you tried to use themes/rkj
Merge pull request #1889 from jerolimov/patch-1

osx-plugin: Do not clear new tab when calling it with an argument.
Merge pull request #1887 from tgkokk/git-slow-fix

Fixed slow behavior when using GitHub wrappers
Merge pull request #1873 from charlesjohnson/bundler-plugin

Update bundler.plugin.zsh
Merge pull request #1872 from gdetrez/new-powerline-range

Update the character used from powerline
Merge 'upstream/master'

Conflicts:
	themes/agnoster.zsh-theme