Introduce BaseCrm::RelatedObjectScope, which allows a better API

With this, related objects can now be created using contact.notes.create,
which is a much better and consistent API.
Adding rake, this is for you, Travis
rake -> rspec spec
Merge branch 'better_related_scoping'

Conflicts:
	spec/support/noteable_shared_examples.rb
0.1.0 - better scoped relations handling