* tkcon.tcl (::tkcon::EvalCmd): add OPT(resultfilter) and 'tkcon

	* tkcon.tcl (::tkcon::EvalCmd): add OPT(resultfilter) and 'tkcon
	resultfilter ?cmd?' to allow optional result filter command.
	Command will be passed result code and data and must return what
	tkcon will return to the user.  Command is run in attached slave.
	Ensure that initial files are sources at level #0.
	Convert args after (--|-argv|-args) into slave arguments and set
	them as the main $::argv/$::argc for propagation.