* main.c, NEWS, doc/make.text: Rename MAKE_TTY* to MAKE_TERM*
* loadapi.c (gmk_eval): [SV 43221] Preserve var buff content for eval.
Support MAKE_TERMOUT and MAKE_TERMERR on MS-Windows.

* w32/compat/posixfcn.c (isatty, ttyname): New functions.
* config.h.W32.template (HAVE_TTYNAME): Define.  Add a prototype
for ttyname.