Adds better chruby detection and setup
[vim] removes duplicate Bundle command
Merges chruby changes into master

Default version didn't work on smileymac.
Fixes #12: sets up bindings differently

Set up bindings for both pairs of key sequences:

cuu1 (up arrow) and kcuu1 (up arrow when keypad mode is active)
cud1 (down arrow) and kcud1 (down arrow when keypad mode is active)
Fixes how $dotfiles variable is constructed

Reading the link on $BASH_SOURCE[0] doesn't work when .bash_profile is
being sourced from .bashrc.  So, fall back to a much simpler scheme:

If $HOME/.bash_profile is a link:
  Read it to get the directory name for the dotfiles repo.
Else:
  Print a warning that it's not set up properly.
  Use the fall-back value: $HOME/github/4moms/dotfiles