Squashed commit of the following:

commit 35c069ac47e92dcac8bdaabf093cff2271f0b0d8
Author: Luisma <luisma@zeetings.com>
Date:   Mon Feb 3 22:23:42 2014 +1100

    Adds modify-vars option.

Closes gh-129.
Fix docs, work on 0.10