Updated plugins & vimrc

- Added back snipmate plugin, it just has a lot of snippets that are
  handy, for instance I use javascript_jquery snippets.
- Updated ultisnips, tried Marc Webers fork for a bit but it still gives
  me errors so switched back to SirVir's version, lets see how things go
  in future and i'll swing towards ultisnips if honzo's snipmate
  snippets are all ported to ultisnips cause I need them.
- Updated vimrc for both snipmate & ultisnips. Using <C-S> as trigger
  for ultisnips so that it doesn't collide with snipmate. Works well for
  now.
Moved to latest powerline

Trying to add rvm information to the statusline. That goes as part of
the powerline project for now.