New theme version, wrap options, inline theme settings and documentation

Please make sure this patch is backwards compatible, also the documentation may be a bit off.
If it all works I will update the `middleman-syntax` readme with the new stuff too.

Update 2014/04/05: Updated and squashed commits to fix new specs which were failing (https://github.com/jayferd/rouge/commit/f8fcf193085e99c513f8167750bb4f33af9fa9a9). Added a hack to allow `css_class: false` instead of `css_class: nil` which I think is more elegant - I'll leave it to you to refactor that and the other `inline_theme` stuff.