The three line change I made previously to implement highlighting for
prompts that ask for single-character input was easy and worked well
for a tiles map, but it didn't look very good for a text map. This
handles both text map and tile map and also adds a configurable
'highlight_prompt' X resource to let the user enable or disable the
feature. The resource template file (win/X11/NetHack.ad, copied to
$HACKDIR during install) now has it enabled by default.
The highlighting--more specifically, the "lowlighting" when no prompt
is active--still looks bad if the map window has a vertical scrollbar
on left edge. I don't have any inspiration about how to fix that up.