Misc clean ups that missed last round

Source/control.cpp

@@ -1274,7 +1274,7 @@ void InitControlPan()
 		pMultiBtns = LoadFileInMem("CtrlPan\\P8But2.CEL", NULL);
 		pTalkBtns = LoadFileInMem("CtrlPan\\TalkButt.CEL", NULL);
 		sgbPlrTalkTbl = 0;
-		sgszTalkMsg[0] = 0;
+		sgszTalkMsg[0] = '\0';
 		for (i = 0; i < MAX_PLRS; i++)
 			whisper[i] = TRUE;
 		for (i = 0; i < sizeof(talkbtndown) / sizeof(talkbtndown[0]); i++)
@@ -2720,7 +2720,7 @@ void control_type_message()
 	}
 
 	talkflag = TRUE;
-	sgszTalkMsg[0] = 0;
+	sgszTalkMsg[0] = '\0';
 	frame = 1;
 	for (i = 0; i < 3; i++) {
 		talkbtndown[i] = FALSE;

Source/effects.cpp

@@ -1021,14 +1021,14 @@ BOOL calc_snd_position(int x, int y, int *plVolume, int *plPan)
 	x -= plr[myplr]._px;
 	y -= plr[myplr]._py;
 
-	pan = (x - y) << 8;
+	pan = (x - y) * 256;
 	*plPan = pan;
 
 	if (abs(pan) > 6400)
 		return FALSE;
 
 	volume = abs(x) > abs(y) ? abs(x) : abs(y);
-	volume <<= 6;
+	volume *= 64;
 	*plVolume = volume;
 
 	if (volume >= 6400)

Source/gamemenu.cpp

@@ -35,8 +35,8 @@ TMenuItem sgOptionsMenu[] = {
 	{ GMENU_ENABLED | GMENU_SLIDER, NULL,            &gamemenu_sound_volume  },
 	{ GMENU_ENABLED | GMENU_SLIDER, "Gamma",         &gamemenu_gamma         },
 	{ GMENU_ENABLED               , NULL,            &gamemenu_color_cycling },
-	{ GMENU_ENABLED               , "Previous Menu", &gamemenu_previous    },
-	{ GMENU_ENABLED               , NULL,            NULL                    }
+	{ GMENU_ENABLED               , "Previous Menu", &gamemenu_previous      },
+	{ GMENU_ENABLED               , NULL,            NULL                    },
 	// clang-format on
 };
 /** Specifies the menu names for music enabled and disabled. */

Source/monstdat.cpp

@@ -123,6 +123,9 @@ MonsterData monsterdata[] = {
 	// clang-format on
 };
 
+/**
+ * Map between .DUN file value and monster type enum
+ */
 BYTE MonstConvTbl[] = {
 	MT_NZOMBIE,
 	MT_BZOMBIE,