Remove all ruby requirements for this plugin

I have always liked it when my vim plugin's didn't require you to compile ruby into vim just to use them.  Mostly because if I ever find myself in a situation where I am not working with ruby specifically, I don't want to feel like I need to have it installed just to work with my tool set.

I have always thought this was a well laid out plugin, but the ruby requirement kept me from using it.  So instead of asking you guys to rewrite it, I thought I would take the time to learn some of the quirks of VimL and do it myself.

I am open to keeping this code on my end, but I think it would be better if it stayed with "it's master".  I really didn't change much on the command side, and there still might be a few bugs here and there, but I think I have taken care of big ones.  I am also open to this being merge into a VimL only branch if you want to keep the two versions separate, but in the same repository.

Let me know what you think and if you have any questions about the code.  I tried to keep my commits small to kind of show you the progression of my changes.


Thanks
-Nick


P.S.  Thanks for the great plugin to begin with!  I learned plenty of new tricks for vim and tmux from doing this!