* _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.

- Plus a bugfix in RC.parse()

- run(): don't block sync()s if one is already running; instead, stop
the task
- get_special(): safely recover from API query exceptions that don't
release the site's SQL lock
- get_notes(): detect protocol-independent links as references, and
ignore links to the current site (#24)
- get_special(): reduce 100-lookup limit to 50, since 100 is already
about three minutes of querying

Resolved conflicts in __init__.py and managers.py