trunk only: preserving context (src files)

Pat Rankin wrote:
> collect them all into some new struct and
> save that separately rather than jamming more non-option stuff
> into struct flags.

This patch:
- collects all context/tracking related fields from flags
  into a new structure called "context."
It also adds the following to the new structure:
- stethoscope turn support
- victual support
- tin support

src/polyself.c

@@ -211,7 +211,7 @@ dead: /* we come directly here if their experience level went to 0 or less */
 		Your("body transforms, but there is still slime on you.");
 		Slimed = 10L;
 	}
-	flags.botl = 1;
+	context.botl = 1;
 	see_monsters();
 	(void) encumber_msg();
 }
@@ -411,11 +411,11 @@ int	mntmp;
 		mntmp == PM_SALAMANDER || mntmp == PM_FLAMING_SPHERE) {
 		pline_The("slime burns away!");
 		Slimed = 0L;
-		flags.botl = 1;
+		context.botl = 1;
 	    } else if (mntmp == PM_GREEN_SLIME) {
 		/* do it silently */
 		Slimed = 0L;
-		flags.botl = 1;
+		context.botl = 1;
 	    }
 	}
 	if (nohands(youmonst.data)) Glib = 0;
@@ -563,7 +563,7 @@ int	mntmp;
 	    You("orient yourself on the web.");
 	    u.utrap = 0;
 	}
-	flags.botl = 1;
+	context.botl = 1;
 	vision_full_recalc = 1;
 	see_monsters();
 	exercise(A_CON, FALSE);
@@ -736,7 +736,7 @@ rehumanize()
 	if (!uarmg) selftouch("No longer petrify-resistant, you");
 	nomul(0);
 
-	flags.botl = 1;
+	context.botl = 1;
 	vision_full_recalc = 1;
 	(void) encumber_msg();
 }
@@ -755,7 +755,7 @@ dobreathe()
 	    return(0);
 	}
 	u.uen -= 15;
-	flags.botl = 1;
+	context.botl = 1;
 
 	if (!getdir((char *)0)) return(0);
 
@@ -921,7 +921,7 @@ dosummon()
 	    return(0);
 	}
 	u.uen -= 10;
-	flags.botl = 1;
+	context.botl = 1;
 
 	You("call upon your brethren for help!");
 	exercise(A_WIS, TRUE);
@@ -960,7 +960,7 @@ dogaze()
 	    return(0);
 	}
 	u.uen -= 15;
-	flags.botl = 1;
+	context.botl = 1;
 
 	for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
 	    if (DEADMONSTER(mtmp)) continue;
@@ -1086,7 +1086,7 @@ domindblast()
 	    return(0);
 	}
 	u.uen -= 10;
-	flags.botl = 1;
+	context.botl = 1;
 
 	You("concentrate.");
 	pline("A wave of psychic energy pours out.");
@@ -1286,7 +1286,7 @@ int damtype, dam;
 	if (heal && (u.mh < u.mhmax)) {
 		u.mh += heal;
 		if (u.mh > u.mhmax) u.mh = u.mhmax;
-		flags.botl = 1;
+		context.botl = 1;
 		pline("Strangely, you feel better than before.");
 		exercise(A_STR, TRUE);
 	}