Revise *status and *controlpanel help output

The list of available commands is quite exhausting. These changes make it possible for users to filter the help output.
This way it matches with the filtering done in CModule::HandleHelpCommand(). For example, "help s" lists commands Set, SetChan and SetNetwork, so I wanted it to list corresponding available variables as well. Would you prefer to reduce the output so that the variables will be output only when the command matches ie. "help" or "help s" won't list any variables?