Update models; Add body classes; Use local name minter

* get active triples from new ActiveTriples repository in github
* add active_triples-local_name gem; add configuration for a local name minter function
* update models for tags and semantic tags to be consistent with OA ontology; add body classes for both
* update annotation body handling
  * track link in annotation to the body instance
  * add helper methods to annotation classes to create and set values for a body appropriate for each type
  * persist body when annotation is persisted
  * resume body when annotation is resumed
  * if applicable, destroy body when annotation is destroyed