Multiple changes for tidyness and upstream changes

* Modified the priorities on all cmdsets to make sure they're above the
exit '9'.

* changed return_ to get_desc_ for all the description functions

* Prettied up the visit command's region list a bit.

* changed containing_room to get_room

* Set up defails for visit condition configurations for areas.

* Created an 'actor' base class which characters and NCPs, etc. could
derive from, so that rooms, props, etc. no longer have status conditions
and equipment and stats and such.