External programs that are "binary" in nature (e.g. file transfer protocols)

now have their output translated to PETSCII equivalents for PETSCII terminals
(but input is not yet translated).
.seq files are now sent untranslated via printfile() and putmsg() to PETSCII
terminals (using the new P_PETSCII putmsg mode flag).
.seq files (and P_PETSCII mode text printed via putmsg) is now converted
(poorly) from PETSCII to CP437 - this is still a work-in-progress.
Remove the remants of WIP and HTMLterm support from putmsg() and printfile().