Changes between 3.2.0 and 4.0.0

Module changes

The following modules have been moved to the willie-extras repository:
- ai
- bucket
- fuckingweather
- nws
- roulette
- twit
- slap
- oblique
The information of the last URL seen in a channel can now be replayed with
.title
The YouTube module was reworked to use the YouTube JSON API
The IP module is now independent of 3rd party services, and requires a local
copy of the (free) GeoLite database. If such database is not installed,
Willie will download it automatically.
.commands now gives better output (no more truncated output due to message
length limit)
Added a unit conversion module
Better handling for non-Unicode page titles in the URL titler
Removed bing support from search
Various minor improvements and bugfixes across all modules

Module discovery was reworked. Willie will now try to load additional modules
from ~/.willie/modules by default, if installed.
The home directory, usually ~/.willie, can now be configured by adding
homedir under [core]
The location of PID files can now be configured by adding pid_dir under
[core]
Willie can now be run as a systemd service
Case sensitivity in nick blocking is fixed
Better handling of ping timeouts (connection problems)
Major code cleanup

Improved Unicode UTF-8 support across all codepaths
Triggers, and the appropriate attributes thereof, are now unicode objects
Decorators were introduced for setting attributes on callables, available in
willie.module
The NOLIMIT return value was moved from the Willie class to
willie.module
Callables with the same name in different modules no longer override each
other
willie.channels is now properly maintained
trigger.isvoice can now be used to determine if a user has voice privileges
Added the max_messages parameter for willie.msg() and willie.say(). See
documentation for details.
Added interval callable support (see documentation for details)
Numerous minor features, and stability and usability fixes