Add vim-ruby-refactoring.
Remove irbrc and pryrc.
Remove closetag.vim.

This was causing a lot of annoying issues when pasting from outside of
vim land (it'd end all HTML tags, even though they were already ended).

Closes #9.
Remap Ag to ctrl+a so as not to conflict with page down (ctrl-f).
Add vim-ragtag.
pre-commit hook needs to always exit with a zero exit code.
Vim snippets.
Fix autocompletion error.