Set undodir to a more appropriate location

Also, make sure that appropriate location exists :)

Per a conversation with tpope, here:

   https://github.com/hashrocket/dotmatrix/commit/6d0886aa81b897b3b4e656b72615bcf79428e314

I'm setting the undodir to an opt-in location. So that that opt-in
location is there by default for dotmatrix installs, I've added a
routine to create that directory if it's not present when you
install/upgrade.
Extract vim refactoring to weefactor plugin
Auto-bind <leader>l to extract RSpec let
Symlink folders and files
Start bringing back .git/safe

Just tried Rails 4 and bin/rails choked on the symlink.  Maybe it can be
fixed, but in the meantime I'm bringing back .git/safe to hedge our
bets.
Don't choke on Vim 7.2
Begin transition to rails.vim projections

:Rnavcommand is deprecated.  Projections are the replacement.  Since
it's easy to do per-app projections, I'm only porting over what I'm
guessing are the almost-universal commands.  Note that old-style
singular factories are supported by :Rfabricator, and new-style plural
factories are supported by the built-in :Rfixtures.

I'm not going to yank the existing :Rnavcommand declarations out from
under everyone's feet, but they will need to be removed at some point.
Give precedence to .git/safe/../../bin

Needed for Rails 4.
Be consistent with bashrc environment var
Support sc alias on Rails 4
Support bin/setup alongside script/setup

Versioned binstubs are hot.
Minimize bettervim shenanigans

This hack doesn't address anything other than a literal vim invocation
(git commit is unaffected), and it makes the command description after
^Z gross.  All to avoid creating a symlink.  Keep it away from me.
Add shortcuts for working with Heroku
Add git patch for new files
Merge pull request #11 from bthesorceror/master

Add heroku shortcuts and allow git -p for new files
Allow homebrew-added zsh completions
Switch to gem projections
Always set undofile

Probably going to have to yank this from sensible.vim :(.
Convert projections
Much better temporary "zooming" for panes

Update to tmux 1.8 to use this