Replace unreliable (featurep 'color) check in rainbow-mode package guard

See #91
Add a binding for vc-git-grep
Merge branch 'master' of github.com:purcell/emacs.d
Use haskell-mode for .ghci files
Add bug-reference-github, and keep github-related config together
Use switch-window package for improved "C-x o" support
Remove binding of C-` for flymake-goto-next-error
Check emacs version within eval-when-compile
Enable delete-selection-mode explicitly, though cua-mode already enables it
Correct note about running prog-mode-hook for ruby-mode
Merge branch 'master' of github.com:purcell/emacs.d
Enable subword-mode in haskell-mode
Merge branch 'master' of github.com:purcell/emacs.d
Don't use ghci-completion in Emacs < 24
Resume using undo-tree
Tidy up init-ruby.el
Tidy up init-css.el
Load magit-svn after magit-key-mode, not magit, to avoid race condition
Move rails code in init-ruby into init-rails
Merge branch 'master' of github.com:purcell/emacs.d