A character manager has the following functionality:
* Keep track of the characters in the agent environment, and their commitments to the story
* Cast characters to give them a place in the story
Behaviour for reaching consensus about performing a given framing operator by
PROPOSEing to all character agents to execute the framing operator, and allows registering
a behaviour to be executed if all ACCEPT-PROPOSAL
Behaviour for asking a World Agent to give control over its world state over to the plot agent
in other words, the Plot Agent asks permission to use this World Agent to send its actions and events to.
Behaviour for asking all Character Agents to select the next action to perform
NOTE: this might have to be changed to a behaviour that asks a GIVEN character agent
to select an Action.