Remove resource

zsh offers a rehash built-in that will reload `$PATH`. I'm not spending
as much time tweaking my dotfiles as I used to, so I don't need the
overhead of reloading everything.
Remove Postgres.app from the path

I've switched to using Postgres from Homebrew, so I don't need
Postgres.app in `$PATH` anymore. I also don't need to set `$PATH` in two
different places. Since the one in `.zshrc` is the one being used, I'm
removing it from `.exports`.
Use rbenv
Add alias to use rhino as js
Remove aliases to start and stop MongoDB

I'm now using `lunchy` to control services. Unlike `brew-services` it
works through pattern matching. It can handle packages whose plist
doesn't match the convention `brew-services` is looking for.

This is essentially a revert of a899514, but changes introduced between
then and now made the revert more work than just doing a regular commit.
Turn on spell check in Vim

Most of my time spent with Vim is for writing commit messages, so having
spell check turned on is useful.