Fixed (maybe) two bugs related to the vim dot:
1. Added lockout to vc.vim_dot in an attempt to prevent a hanger.
    This is *not* guaranteed to work! For now, use the dot command only if you are willing the kill the Leo outline!
2. vc.vim_dot now saves/restores the dot, so that, fore example, the 4. command does not change the dot.

Leo build: 20140822054225