* Added exclusions module with a fully implemented ExclusionsDB that can pull
  from multiple sources for different sites.
* Moved CopyvioCheckResult to its own module, to be imported by __init__.
* Some other related changes.

Also implementing MWParserFromHell, plus some cleanup.

* _ResourceManager: allow resources to be named anything as long as they
  inherit from the base resource class; gave resources proper names.

* Renamed BaseCommand to Command and BaseTask to Task; applied renames
  throughout earwigbot.commands and earwigbot.tasks.

* Data: refactored argument and command parsing to be completely internal.
  Added docstrings to attributes. Applied changes to Frontend.

* IRCConnection: improved such that we accurately detect disconnects with
  server pings; timeout support. Applied changes to Bot.

* Updated documentation and other minor fixes.