Only use smex in Emacs 24
Require and enable ipretty-mode
Remove pretty-mode, but use Emacs 24's global-prettify-symbols-mode if available
Add note about escaping the tyranny of ido-mode in find-file

See #175
Merge remote-tracking branch 'purcell/master'
add yasnippet
Merge branch 'master' of https://github.com/gsmlg/emacs.d