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.

include/context.h

@@ -80,7 +80,6 @@ struct context_info {
 				/* 8: travel */
 	unsigned startingpet_mid;
 	int	 warnlevel;
-	int	 in_lava_effects;	/* hack for Boots_off() */
 	long next_attrib_check;	/* next attribute check */
 	long stethoscope_move;
 	short stethoscope_movement;