- Rename EventManager --> EventController
 - Move test data files specific for EventController tests into separate folder (under controllers/events)
 - Add Event's owner check before returning the Event in getEventById() action
 - Extract a method creating json response into abstract superclass
 - Remove the issuing of the error message for get/create Event actions
Merge branch 'master' into j00ff/speakers_tab
Add unit tests for deleteSpeaker action; the commit is intended to save the work before possible negative outcome of playing with bidirectional many-to-many associations (Speakers <--> Speeches)
 - Modification of the Global.java class to allow saving many-to-many (speech<-->speaker) relations on application start
 - Add overriddend delete() method to the Speech and Speaker entities cleaning up references to themselves upon deletion
 - Modify initial-data yml populating storage with the referenced speech<-->speaker entities
 - Add unit tests to check the modifications to the objects referencing speaker when the speaker is deleted
Fix the test method