plugin groupblog, tmp (mam, rsm): some style improvments/fixes: - renamed variables nammed after reserved word/module - removed class variables which are not needed - removed external parenthesis from asserts - in mam.MAMPrefs, removed default value for default argument, as None can't be used - (groupblog) extended docstring for DeferredItems and DeferredItemsFromMany

# TODO: remove this when RSM and MAM are in wokkel
import wokkel
from sat.tmp.wokkel import delay as tmp_delay, pubsub as tmp_pubsub, rsm as tmp_rsm, mam as tmp_mam
wokkel.delay = tmp_delay
wokkel.pubsub = tmp_pubsub
wokkel.rsm = tmp_rsm
wokkel.mam = tmp_mam