Switch from vundle to NeoBundle

Seems like this might make installing unite easier
Add some headers
Add vim-ruby as a bundle

Sure it will come in handy some day
Add bundles for unite
Add some bindings and settings for unite

These are taken from
https://github.com/terryma/dotfiles/blob/master/.vimrc
Move completeopt with the rest of the builtin settings
Map leader to comma

- Get rid of easymotion custom leader
- Get rid of some tags stuff I don't use