[Groff] Extending .tm to allow for file handles

[Tom Borawski]

I was wondering if their is any possibility having .tm write
to anything other than STDOUT ? It would make managing forward
references (when used with 2 groff passes) much easier.

In other words for a forward reference (now I have to)

.so hand-edited-STDOUT-captured-text-with-reference.txt

{rest of document}

.tm \*[reference-info]


Is there any way this could be:

.so groff-auto-file.txt

{rest of document}

.tm FILEHANDLE \*[reference-info]