Better Rails 4.0 support and html2haml fix

- Several minor updates to make devise + cancan code work with Rails 4.0.0 (release).
- Added gem path reload command just after **bundle install** to make sure we won't run into problems with missing gems while doing **require 'html2haml'**

It was sort of a quick fix for those wanting to start right now. For better and deeper Rails 4 integration a full revision of all dependencies is required.