Allow custom IDs to be specified when calling load_resource

Support for namespaced models and engines

Specs fail when running in a freshly installed environment.

Add .travis.yml for building cancan on a lovely Travis CI service

Compatibility fix for rspec-instafail and rspec1

Fixed documentation for skip_load_resource and skip_authorize_resource.

Load datamapper class methods via append_extensions.

This relaxes the previous requirement that cancan has to be loaded
before any models are. append_extensions will apply to all
previously loaded models as well as ones loaded after.

Make CanCan Default Message a translatable text.

Fixes bug in mongoid_adapter with empty conditions hash

1) remove all empty conditions hashes from the rules, they are included
 in the records through `@model_class.all`
2) only process can rules if the new and old rules lists are the same
  length (meaning there were no empty conditions hashes)
3) always process cannot rules

* adds mongoid query that matches every record when
rule.conditions.empty? is true

DataMapper adapter improvements

Thanks dkubb!