Massive cleanup/rewrite

I basically just pulled in my own dotfiles repo, here, with a few other additions. I've tried to avoid having anything that's strictly my preference here. I pulled mine in because I've done a lot of work with them to be very robust and flexible. 

Changes:

- Added a script which will set some sane default preferences on OSX (see `osx_defaults.sh`)
- for vim and plugins, most everything happens via git and git submodules (using Pathogen rather than Vundle), so we no longer have to start vim running `VundleInstall` as we'd previously done
- a full ZSH configuration using [Prezto](//github.com/GoodGuide/prezto)
- should be linux and mac compatible 
- better linking/install script
- should be `docker-build`able so one could create, for example a `Goodguide/dev` docker image which could be pulled down to any system and have a sane working env ready to go
- some helpful scripts that I have been using forever
  - including one called `safe-reattach-to-user-namespace` which allows the same tmux config to be used on OSX and Linux and still have copy/paste work correctly on OSX
- Added an iTerm color scheme 

It's still vim/tmux centric, although I hope we can change that in the coming months (I would look to @mjsteger and @goodsimon for some good emacs defaults and to @Mattbot and @emmasteimann for some good Sublime defaults)

/cc @namick @joshuabates @dweinand -- I would specifically like your scrutiny over the vim config here, seeing as we are the regular vim users here. My goal with this is to have some sane defaults that everyone could work with, even if it's not everyone's preference. I'm hoping you guys can help me by finding any cases where I assumed too much or forgot anything you would consider to be the bare minimum...