Updated to work with Rails 4 and Ruby v2

I have updated to work with Rails 4 and Ruby 2.0.0 patch 247. The only thing I haven't done is made the necessary changes to work with Strong params but I have updated the readme.md to show the extra gem needed in order for this to work. gem 'protected_attributes'
When I have more time I'll sort this out but in the mean time this seems to work fine for me. I also had to remove linecache19 and the debug gems from the development environment.

I guess if you find it useful you may want to create a Rails 4 branch for this?