wounded legs fixes

Document 'HWounded_legs' vs 'EWounded_legs'; they aren't used the way
other properties use their intrinsic and extrinsic values.  And they
switch from hero to steed when riding.  (Can't start riding when
hero's legs are wounded and the steed's legs magically heal when hero
dismounts, so existing wounds never transfer from one to the other.)

Having one leg become injured when the other already was would cure
the other leg but keep the longer of their two timeouts for the new
injury.  Eliminate that mystery cure.  Since their timeouts aren't
tracked separately, the best that can be done is to make both legs
eventually recover at the same time.

Make ^X report which leg is the wounded one when only one of them is.
(It already implicitly reports the both-legs case by using plural.)

When zapping a wand of probing downward while riding, include wounded
leg feedback for the steed.

Simplify wounded leg feedback when probing self a little bit.

Make drinking blessed potions of full healing cure wounded legs for
hero when not mounted or for steed when mounted.  (The latter is a
bit strange--hero drinks potion, steed gets affected--but it's magic.)

Make drinking uncursed potions of full healing or blessed potions of
extra healing cure wounded legs for hero (but not steed; the magic
either isn't that strong or maybe not that reliable...).

doc/fixes37.0

@@ -729,6 +729,10 @@ allow fire-command to automatically use a polearm, if wielding it
 make '$' command also count gold carried inside containers
 fleeing leprechauns bury their gold after teleporting
 allow #tipping container contents directly into another container
+when one leg is wounded, have ^X report which (already used plural if both)
+wand of probing used on steed ('z >') didn't include wounded leg(s) feedback
+getting wounded in one leg when the other was already wounded miraculously
+	healed old leg and kept longer of their recovery timeouts for new one
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository
@@ -1312,6 +1316,10 @@ track peak maximum HP and peak maximum energy/power; no noticeable effect
 give some dragon armor extra effects when worn
 issue messages during last stage of food poisoning/terminal illness countdown
 	when hero's demise is imminent
+drinking blessed potion of full healing heals wounded legs, either hero's or
+	steed's (when riding, wounded leg injury applies to steed, not hero)
+drinking uncursed potion of full healing or blessed potion of extra healing
+	heal hero's wounded legs when not riding; no effect on steed if riding
 
 
 Platform- and/or Interface-Specific New Features