Fixed small error in notification message
Refined player movement method
Fixed use of deprecated method
Added narration for player movement

This commit also makes the DungeonUniverse class more uniform
with how it returns a range of players (i.e., from a certain room,
or the whole list of players) by returning iterators over players.

Added for convenience with the DungeonDispatcher class is a method
that uses an iterator over players to place their PrintWriters into
an array, useful for the methods in the DungeonDispatcher class.

The Room class now has a getNumberOfPlayers() method.
Added 'move to here' narration type
Tidied up comments in DungeonNarrator
Fixed a bug with movement narration

Players now receive narration of another player's movement out of
the room at the right time, and players in the destination room
now receive "incoming" narration at the right time.
Enhanced comments around some movement code
Re-implemented 'look' action

This commit includes the addition of a look method in the
DungeonUniverse class.
Removed a weird narration phrase
Refined descriptions of rooms

Notably: added a describePlayers method to the Room class that
returns a list of players in the room (from a certain player's
perspective).
Added narration for player connects/disconnects
Player connects/disconnects now trigger narration
Removed unneeded comment
Implemented 'say' action

Implemented the action code in the DungeonProtocol class. Then
added a synchronized method 'say' in the DungeonUniverse class
that calls the appropriate methods in DungeonNarrate and queues
the narration in the event queue.
Implemented 'yell' action

Also included is a new method in the Room class
that returns an iterator over adjacent rooms.
Pulled 'known bugs' section from readme and opened a todo file
Populated todo file with standing tasks