Add \r to the beginning of PS1

This keeps it at the beginning of the line, even if there is typeahead.

Thanks to http://superuser.com/a/738771/39697 for showing the correct way to
do this.
Update KeyRemap4MacBook
Make a shellcheck suggested change to SUDO_PS1
Enable global Python argcomplete completion
Add (commented out) suggestion to complete source activate
Update KeyRemap4MacBook prefs
Merge branch 'master' of github.com:asmeurer/dotfiles

Conflicts:
	Library/Preferences/org.pqrs.KeyRemap4MacBook.plist