Instead of passing around pointers to the Server, Server::Get() returns
the server's pointer (simplifying some things a good bit).
As a result, headers have been cleaned up, and some redundant KeyMaps
have been placed in Maps.h.
The room directory window now has an accounts menu, to allow the user to
filter rooms by account― and a "category" column has been added, which can
optionally be filled by the protocol for more semantic sorting of rooms
(Through "category" slot of IM_ROOM_DIRECTORY).
This window (Chat→Room directory) is to be used for either a list of
publicly available rooms (in most protocols), or for a list of
joined-but-hidden rooms (as it'll used with libpurple, to list its
ChatBuddies).
Each room is sent individually from protocols using IM_ROOM_DIRECTORY
messages sent in response to a IM_GET_ROOM_DIRECTORY message.