Add .irbrc. Use Brice (successor to wirble).
Drop neocomplete for autocomplpop and simpler dictionary support

Neocomplete was so promising, but fell down on a couple things:

1. Needed to compile vim with lua, and failed spectacularly when lua
wasn’t present.
2. Sometimes when backspacing, moving backwards (I know, arrows in
insert mode, bad me), behavior was really weird, and required leaving
insert mode just to move a few chars.

Kept neosnippet, but it has no integration with autocomplete, which is
fine.
Emacs-like movement in insert mode