Add context and term factory to test the vocabulary
Refactor modules/vocabulary_spec to use vocabulary factory
Fix ::Vocabulary.meta_terms_for_set and count thereof
Add migration to ensure meta_keys_meta_terms are unique
Transfer only meta_term_meta_data when transferring m.resources between terms

Conflicts:
	app/controllers/app_admin/meta_terms_controller.rb
	app/models/meta_term.rb
Fix copyright issues