Slate: always let Textual go full-screen

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Vim: add some more mappings to get out of insert mode

I've been using `jj` for a while now (and incidentally it was hard to
type that), but going to also see what `jk` and `kj` feel like.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Vim: add mapping for Ruby 1.8 -> 1.9 Hash syntax

I've had this floating around uncommitted for a while, wondering if I'd
ever stop needing it. Still using it pretty regularly, so in it goes.

Signed-off-by: Wincent Colaiuta <win@wincent.com>