- Modification of the Global.java class to allow saving many-to-many (speech<-->speaker) relations on application start up
 - Add overriddend delete() method to the Speech and Speaker entities implementing cleaning up references to themselves upon deletion
 - Modify initial-data yml populating storage with the referenced speech<-->speaker entities
 - Add unit tests for delete Speaker action
Merge branch 'master' of github.com:abarinoff/ConfLabs