Some bug fixes.
Some bug fixes.

birkenfeld/docopt.rs,birkenfeld/docopt.rs,alexcrichton/docopt.rs,zsiciarz/docopt.rs,brandonson/docopt.rs,brandonson/docopt.rs,zsiciarz/docopt.rs,zsiciarz/docopt.rs,brandonson/docopt.rs,alexcrichton/docopt.rs,birkenfeld/docopt.rs