[seen, version, xkcd] Update to API 4.0, issue #276
[url] Update to 4.0 standards, fix .title
[search] Update to 4.0 standards, fix registration of last url
[oblique] Move module to -extras

The code is a mess, half of it doesn't work, half of what does work is
duplicated by other, better modules, and everything else is so confusing
to use that it's just not worth it.
[admin] Cleanup: Change attribute names from "willie" to "bot".
[admin] Cleanup: Callables attributes changed to decorators.

Buggy regexes changed to less restrictive commands. They will accept some
things that were not accepted before, but the end result is same, as server
will ignore wrong commands.
 -Join now also accepts channels not starting with #.
 -Mode now accepts modes not starting with +, - or \ (accept \ was a bug).
[admin] Cleanup: readability fixes.
[admin] Add new commands set and save.
[irc] Fix PART message being sent in wrong format.
[admin] Fix handling of part messages.
[search] remove Bing support

It barely works: outputs unnecessarily long links which are never relevant to what you're looking for.
Also, nobody uses bing apart from Microsoft employees (and they only do so because company policy forces them to do so)
[units] Fix syntax error

Someone changed the conditions and forgot to test his code before committing
[seen] Fix import
[core] Properly handle unicode in bot.reply

The previous fix for this (ee1f30f) broke some modules.
This commit make sure we handle cases where string is already of type unicode
[contrib] fix "Executable path is not absolute" when stopping the willie service
[core] Eliminate useless error message when the bot quits
[url] Fix error on Unicode pages
[web] Fix ability to pass custom headers

Also make the default user agent say Willie, not Jenni
[url] Respect page's reported encoding, otherwise try UTF-8

Also, fail silently if the above don't work.
[core,url] Fix error where title was not shown for wikipedia pages

Also remove cruft from web.py, urllib knows how to handle redirects itself