Greatly expanded chat options

- added a bunch of subcommands to chat.  Now, the 'chat' command
includes the ability to create, delete, manage, and gather information
about chat channels.  The server now contains a chatManager component
that can create and store an arbitrary number of chat channels, as
needed.
- still need ability to optionally password protect a channel
- still need to expire old channels, and be able to set some channels to
never expire.