Removal of EventBusChangeRecorder

Removal of EventBusChangeRecorder

- Reasons to remove :
  1) AbstractCommonSubsriber notifies event bus and then event bus
     performs operations on AbstractCommonSubsriber - what is the
     reason for this indirection?
  2) AbstractCommonSubsriber does nearly nothing; only brokes input
     events to subscribers based on EventType.
  3) There are only two possible types of subsribers that have
     common parent in which all logic is performed.
- Correction of synchronization in AbstractCommonSubscriber -
  concurrent set is not enough, because in postData(..) method this
  set is accessed twice --> explicit sync using monitor or lock is
  required.

Change-Id: Iac70127b7ebbbbe0c0ff849120818ddf71278a94
Signed-off-by: Jaroslav Tóth <jtoth@frinx.io>