Adding spf13 config for vim

This adds the popular spf13 config for vim, which adds a ton of neat features, like mouse support, function definitions, PHP Docblock building commands, etc. Learn more at https://github.com/spf13/spf13-vim.

This probably shouldn't go into master yet, since it uses something called Vundle (a vim installer) to install bundled plugins. This makes the stdout go a bit funky (it starts using half of terminal instead of all of it). Everything works fine though, and you get much better vim.*

\* Much better vim results may vary. I'm planning to test each of the bundled plugins and remove the ones that we may never need.