in_lava_effects (trunk only)

The in_lava_effects flag should never be saved and restored; putting
it into the context struct was a mistake.  Move it to the iflags struct
(where the branch code already has it).  I haven't bumped the EDITLEVEL
setting.  Save and bones files from more that a few days ago were breifly
invalid but should be viable again.  Save and bones files from the past
couple of days are now no good; sorry about that.

src/do_wear.c

@@ -154,7 +154,7 @@ Boots_off()
 		    !Levitation && !Flying && !is_clinger(youmonst.data) &&
 		    !context.takeoff.cancelled_don &&
 		    /* avoid recursive call to lava_effects() */   
-		    !context.in_lava_effects) {
+		    !iflags.in_lava_effects) {
 			/* make boots known in case you survive the drowning */
 			makeknown(otyp);
 			spoteffects(TRUE);