Remove redundant syntax highlighting

Newer versions of vim (such as 7.3.923) syntax highlight Rackup and JSON
files correctly. In the interest of keeping the dotfiles slim and our
machines up-to-date, I think the solution is to remove these from
dotfiles and install a newer version of vim in thoughtbot/laptop:

https://github.com/thoughtbot/laptop/pull/118
Adds local configuration file for vim bundles
Allow for a local tmux.config file
Updates dotfiles to have .local files as needed

* in favor of the old way of #DO NOT EDIT BELOW THIS LINE, dot files
* were changed to have local config files - updates local dotfiles ot
* match this preferred pattern
Adds git plugin back for git branch auto completions
Load RVM
Color and alias tweaks
Adds mysql back into path