ack: Search emblem files
git: Safer rebase on OS X. Remove unnecessary hub config
ssh: Heroku virtual hostnames for multiple identities

Assumes existence of ~/.ssh/identity.heroku.{personal,work}
(not stored in this repository of course)

Added as part of heroku-accounts plugin:
https://github.com/ddollar/heroku-accounts
tmux: Mouse can resize panes and select window
zsh: Adjust PATH. Remove python shared, add node shared, add cwd bin
ruby: Default system-wide ruby to MRI 2.1
hub: Update hub shell install hook
git: Use histogram diff algorithm by default
zsh: chruby support
zsh: Update virtualenvwrapper configuration