nickserv: Add a seperate module that implements R:nick extban type
nickserv: Fix some race cdns related to a user logging out mid-operation
nickserv: Fix a silly bug
Make nicklist comparison for R: extban case insensitive
Implement logout action
nickserv: Seperate actions for login permission action and post-login action
cmode_b: Re-calculate extbans after a user login or logout
installer: Don't delete everything, just py/pyc files

This way we still get fully fresh code, but we don't lose logs and storage.