This is to deal with the hundred lines of command splurge when one previously typed "help"
Modelled somewhat on the mysql console
One can still type help <command> to get per command help at any point.
Categories capitalized to avoid conflict with the all-lowercase commands (except for commander system, as of yet).
Does not affect command parsing or any other aspects of the console apart from the help system.
Backwards compatible with existing modules.
This is necessary so that code in HttpServer can use framework facilities such as the thread watchdog for monitoring purposes.
Doing this shuffle meant that MainServer was moved into OpenSim/Framework/Servers
Also had to make OpenSim.Framework.Console rely on OpenSim.Framework rather than the other way around since it in turn relies on HttpServer
MainConsole and some new interfaces had to be moved into OpenSim/Framework to allow this. This can be reverted if parts of OpenSim.Framework stop relying on console presence (cheifly RegionInfo)
