Customizable location for vimbackup, vimswap, etc.

The first commit adds a feature that I found to be missing. Personally, my home folder is cluttered up enough as it is, so adding this option allows for moving the backups/views/undo/swap files to a different directory (in my case .vim/vimbackup, etc).
The second commit is simply a lot of cleaning up of the .vimrc file. It fixes indentation and makes all comments have more of the same formatting - generally makes the file more readable.