Print filter enhancement: The printer init statement COMMAND=SBX:filter,... now supports two optional macro arguments, $PREFIX and $SUFFIX, which evaluate to the current prefix and suffix options. For example, given the following printer init file:
DEVICE=TEST
COMMAND=SBX:PFILTR,$PREFIX,$SUFFIX
PREFIX=TEST.PFX
SUFFIX=TEST.SFX
the print filter PFILTR.SBX would receive "TEST.PFX" and "TEST.SFX" as the 7th and 8th arguments. The first 6 arguments to a printer filter are always preset to STS,FSPEC,PRINTER,SWITCHES,COPIES and FORM.
