quich frontend, primivius (chat): better avatar handling: - new getAvatar method in QuickApp which request vCard if avatar if needed and return default avatar is no avatar is found - frontends based on quick frontend can now specify if they handle avatar or not using AVATARS_HANDLER - when avatar is updated, occupant widget(s) and all message widget(s) of the concerned entity are updated

# FIXME: remove this when RSM and MAM are in wokkel
# XXX: the Monkey Patch is here and not in src/__init__ to avoir issues with pyjamas compilation
import wokkel
from sat.tmp.wokkel import pubsub as tmp_pubsub, rsm as tmp_rsm, mam as tmp_mam
wokkel.pubsub = tmp_pubsub
wokkel.rsm = tmp_rsm
wokkel.mam = tmp_mam