uses vundle for Bundle like management of vim plugins

* Vundle makes managing dependencies easier than pathogen ( in my opinion ), because you can have a 'Gemfile like' list of plugins you want.

* This commit also starts to break down the vim config into seperate included files in the master vimrc.

Currently this change incudes all the vundle code, we could include vundle as a submodule instead ( to account for future changes ), but if its already there it's one less step to begin with.