Names are adapted to DOS 8.3 file names, PETSCII adaptions of core.fth
are reverted (DOS uses ASCII), the input test is disabled, since no
way was yet found to inject keystrokes into dosbox. And some tweaks
were applied to ans-shim.fth and the golden files to make the first
tests (preliminary & core) to pass.
interpret-via-tib instead of clearing it after.
This way, commands after a .fth include can be passed to v4fthfile.com,
e.g. a bye to terminate a make-controlled test run.