Fix code standards
Add a few comments to mapper interface
adding Conversation entity test, add missing dependency : "rhumsaa/uuid": "2.*"
added  Entity\ConversationReceiver Test
added  Entity\Message Test
exclude entity interfaces from coverage
 - added Form\NewMessageForm test
 - added Form\NewMessageForm test
added Form\NewConversationForm test
added View\Helper\ZfcUserPmHelper test
update @covers
Pmservice class Test 70% added
update changelog
- undo add setDeleted($deleted) in ConversationReceiver because already in there.
- added Form\DeleteConversationsForm test
- Service\PmService  test fully implemented
- added Factory\View\Helper\ZfcUserPmHelperFactory test
- added Factory\Service\PmServiceFactory test
- added Factory\Mapper\DoctrineORM\PmMapperFactory test
- added Factory\Options\ModuleOptionsFactory test