Fixing easygit bash completion, mostly by accident.

I was poking around at the easygit bash completion tonight, and I accidentally seem to have fixed it.

Completion is this gnarly mess of what amount to global variables (though bash tricks you by declaring them as 'local'!). I think they changed the way some data was passed around between when the `eg` completion script was last updated and now.

I'll use my updated copy of easygit for a couple of days to make sure everything seems to be working, but honestly it can't be any worse than it was, which was totally broken...