quick frontend(widgets): improved handling of multiple instances of widgets: when a widget was recreated, a new hash was created with a suffix, making hash matching difficult and bug prone. This has been changed to use a list of instances instead, this simplify the code and avoid issues while looking for existing instances of a widget.

# XXX: the Monkey Patch is here and not in src/__init__ to avoir issues with pyjamas compilation
# TODO: remove this when changes are merged in Wokkel
from sat_tmp.wokkel import install
install()