Implement the host cloaking module
Slightly increase the priority of setting usermodes on connect
This is mainly so that when cloaking is enabled on startup, the cloaks are
applied before conn_join kicks in and real hosts won't leak.
Merge remote-tracking branch 'origin/module-cloaking' into module-cloaking

Conflicts:
	txircd/modules/extra/cloaking.py
	txircd/modules/extra/conn_umodes.py