Remove boxen

Going to put this on a test account until I get it the way I want it.
Bump ruby-version
Set vim so that the cursor can go past the final character
Ensure rack comes before rails in default-gems
Put ruby/rbenv scripts in optimal order
Ensure default-gems are symlinked before Ruby is installed
Replace dotfile directory references with $DOTFILES var
Revert $DOTFILES reference

It shouldn't be set yet. I need to source the .zshenv first.
Modularize bootstrap sub-scripts

DRY FTW