remove conference role list_for_moder, not used
conference announce when user left room
add plugins to make_*.py
conference gui preferences
save outer_sizer in self object (dlg_settings)

and fit tabs 1-4
conference preferences fit tab p3
conference preferences in Conference tab
conference option receiver_status
conference GUI option password
conference expand text preferences
conference set role of invited user to user
move password feature from to add_password plugin

conference still can set password[_tip], but
all work is performed by add_password
import version in torchat.py
fake_user_agent plugin
disable_echo plugin
conference shows status and role only in !list
allow multiple ping/pong on one connection
ping plugin
global variable in disable_echo moved to global ns
ping plugin calls GUI via CallAfter

calling GUI directly from network thread is dangerous