Use better-snipmate-snippet instead of just snipmate

snipmate-snippets no longer exists, and better-snipmate-snippet includes
snipmate anyway.
Install vim YouCompleteMe plugin

See https://github.com/Valloric/YouCompleteMe for details for full
installation guide.
Install "localvimrc" plugin

This lets you specify local Vim settings for each project without
effecting Vim settings globally. Also add ".lvimrc" to global git
ignore.
Use Vim UltiSnips instead of better-snipmate-snippet