Also changes ConsoleUtil.CheckFileExists to CheckFileDoesNotExist() since this is more meaningful in the context, even though it does result in double negatives.
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.
Melanie