experimental hitpointbar change

For tty, make hitpointbar blink if current HP falls to the critical
HP threshold.  Doesn't require status highlighting.  Not changed:
when status highlighting is active, use the HP color but force the
attribute to be inverse (plus blink if the criterium is met) rather
than whatever the HP highlight specifies.

For curses, do the same thing.  It used to honor HP attribute for
hitpointbar, now it behaves the same as tty:  always inverse, maybe
combined with blink.  The new code assumes that inverse and color
can be turned off without turning off active blink in the process.

I had intended to make hitpointbar be a full-fledged status field
(which happens to be rendered on top of title) so that it could be
highlighted differently from hit points (mainly so that one could
highlight up and down changes while the other showed percentages).
This is less versatile than that but much simpler.

doc/fixes3-7-0.txt

@@ -2611,11 +2611,6 @@ tiles: male and female variations in monsters.txt; tested only with tile2bmp
 tty: use bright colors directly on supporting terminals
 tty: if a message is marked urgent, override message suppression initiated
 	by user having typed ESC at previous --More-- prompt
-tty+DECgraphics: when ready to print a normal character after having printed
-	a line-drawing character, don't switch back to normal character set
-	unless current char is one that gets rendered differently as a line
-	drawing char (mainly lowercase letters) so that we might be able to
-	avoid the need to switch to line drawing for next char that uses that
 Unix: can define NOSUSPEND in config.h or src/Makefile's CFLAGS to prevent
 	unixconf.h from enabling SUSPEND without need to modify unixconf.h
 Unix: support --nethackrc=filename on the command line; same effect as
@@ -2628,6 +2623,9 @@ X11: echo getline prompt and response (wishes, applying names) to message
 	window and dumplog message history
 X11: fix map expose area, no longer leaving black bars on the map
 tty and curses: support italic as text attribute
+tty and curses: when hitpointbar is displayed, make it blink if current HP is
+	below the "critical HP" threshold (where prayer treats being injured
+	as major trouble)
 
 
 NetHack Community Patches (or Variation) Included