Added system wide configurations.

This was accomplished by breaking having two separate files:

* customization.vim : Essentially a .vimrc without vundle
* vundle.vim : The loading code for vundle

The .vimrc then simply sources these two files.  First vundle is loaded
and then the customizations.

Since this this all happens in the vimrc, this means that all the
customizations are loaded before any plugins.  This was needed for
customizations that affect plugins themselves.