Vim: Add bundle vim-surround

surround.vim : quoting, parenthesizing made easy

- cs<Q><Q'> : change surround <Q> to <Q'>
- ds<Q> : unsurround with <Q>
- ys<Range><Q> : insert suround <Q> to text <Range>
- (visual) S<Q> : surround visual-selected text with <Q>
Vim: Add bundle vim-repeat

The '.' command now also works for surround.vim commands.