added WRITE test
fixed FIXME: moved reclen, serial, filenum option parsing to the right place
moved option parsing to new config.py module
hide_keys --> shoow_keys(False); commenting improvements
BAckspace handling in text files was incorrect -- chr *is* printed to the file, you just don't see it if you cat the output under linux.
allow using data segment to store & read back data - this will shadow any variable stored in the same area