win32gui, win32tty: add support for looking for sysconf in %COMMONPROGRAMFILES%
first and for user config file in %USERPROFILE% (improves support for
multi-login Windows environments)
-win32gui: missing sys_early_init() call could result in "rnd(0) attempted"
win32tty: support for 'selectsaved' option for menu of existing save files
to choose from at game startup
tty: add window port routines for saving/restoring message history