configure would break checking curses.h.

Will backport.

without prior setting of the userptr.

Will backport.

aren't fixed yet.

Includes a first test (for compiler).

Will backport.

Squash new warnings from VC 7.1 about mixing signed and
unsigned types in comparisons.  I can see why `len` was
changed to size_t here, but don't see why `i` was also
changed.  Change `i` back to int.

Move declaration of local `flags` to top of block.

Revert previous checkin, the check is for <, not ==.  i is unsed in non-debug builds, but is used in debug builds

for 2 different values without changing.  I think this was the intent.
The unused warning only occurs when not building in debug mode.

Fix icc warnings: try to set TCL_UNIX_FD for #if TCL_WIN_SOCKET == TCL_UNIX_FD.  res is not used, add a XXX comment

fail everywhere.

This inappropriately disabled some capabilities which exist.

Now test for readline in -lreadline, if not found there, try it
in -ltermcap only if not in -lreadline.  If both libraries are
required, there will need to be more work, but I'm not sure
under what conditions both libraries would be required.