Released netscript version 1.6.4.

addition of the $; variable, for reverse/negative input matching. changed ns_init() and ns_incoming() to pass extended data. addition of -a, to allow interactive use with third party programs. changed program dumping to pass CTRL-C requests to the third party program. changed the program dumping method used. changed -x to comply with the new program dumping method. addition of -B, to send netscript to the background. addition of -g(use twice for more generic mode) to enable the GUI/GTK mode of netscript. addition of -G to set a title to the gui. fixed some minor/uncommon bugs.