Paranormal Investigator implemented, Forceroles feature added (helps with testing), and assorted fixes

Paranormal Investigator implemented -- this changes the role name if a wolf or tanner is seen. Displaying roles now uses role_as_text in order to convert the PI role to say PARANORMAL_INVESTIGATOR regardless of actual role.

Forceroles now uses a similar method to roleset in order to add roles that will definitely be given to players. This is especially useful when testing (though it could be used in an actual game if desired). FORCE_ROLES can be set to false to disable this.

A few other small fixes were implemented as well, including a bug where doppelinsomniac would say it was "still the insomniac" if it hadn't switched (though the player is actually still the doppelganger).