- new QuickApp.ENCRYPTION_HANDLERS class attribute, if True (default), encryption handlers are set
- encryption plugins are retrieved on startup and cached in QuickApp.encryption_plugins list
- QuickChat's encrypted boolean attribute indicate if a session is currently encrypted. This is updated
automatically if ENCRYPTION_HANDLERS is set
- if ENCRYPTION_HANDLERS is set, messageEncryptionStarted and messageEncryptionStopped are called when
suitable.