fix part of github issue #1285 - cursed curses

Issue reported by g-branden-robinson:  vertical status panel ended
up with an extra closing paren on the energy line, and sometimes
popups left some text and/or border to the right of the map.

I haven't been able to reproduce the energy anomaly.  It is possible
that it is dependent on the version of curses.

This fixes the leftover popup traces that the base window catches
(and hangs onto) when there is extra space to the right of the map.
Erasing a popup prior to deleting it suffices to make base window
forget it.

I have a more elaborate fix that covers the space to the right of
the map, when there is some, with an extra window and erases that
window when refreshing the map.  It works but adds a bunch of code
that we can get by without.

Issue #1285 is still open.

doc/fixes3-7-0.txt

@@ -2192,6 +2192,9 @@ curses: allow changing default colors with the 'palette' config option
 curses: if messages have been issued during start-up (for instance, warnings
 	about issues in run-time config file), prompt user to press <return>
 	so that they can be read before curses erases the screen
+curses: when the map was narrower than the space set aside for it, wide popup
+	windows could write into the unused space and whatever was written
+	there would stick after the popup was removed
 documentation: when building plain text Guidebook.txt from Guidebook.mn, avoid
 	attempting to use CR font; change doesn't affect building Guidebook.ps
 	which utilizes CR to get various instances of fixed-width text