Ongoing work on OTR.
Adds basic OTR settings
Adds OTR fingerprints and private keys settings. Fixes multiple issues.
Fixes exception on shutdown caused by different context used in unregisterReceiver.
Makes EventDispatcher load listeners just before event execution and not on Command creation to fix problems when some of listeners were unregistered after the command was scheduled. Logs exceptions.
Fixes multiple OTR related issues.
Integrates OTR plugin bundle. Fills the javadoc.