Use functools.wrap to preserve method metadata

This makes introspection a lot more useful as decorated methods now show
their original name instead of the wrapper names 't' and 's'.
List actor methods, actor functions, etc.

This might be useful in introspection, as a way of divining an actor's
(possible) inboxes and outboxes.
Merge branch 'introspection'

Conflicts:
	guild/actor.py

Adopted the useful bits from branch 'introspection'.