Replace hacky flag abuse with timer (which can be used later when developing pushing sprites).

src/d_player.h

@@ -241,6 +241,7 @@ typedef enum
 	pw_underwater, // underwater timer
 	pw_spacetime, // In space, no one can hear you spin!
 	pw_extralife, // Extra Life timer
+	pw_pushing,
 
 	pw_super, // Are you super?
 	pw_gravityboots, // gravity boots

src/dehacked.c

@@ -7118,6 +7118,7 @@ static const char *const POWERS_LIST[] = {
 	"UNDERWATER", // underwater timer
 	"SPACETIME", // In space, no one can hear you spin!
 	"EXTRALIFE", // Extra Life timer
+	"PUSHING",
 
 	"SUPER", // Are you super?
 	"GRAVITYBOOTS", // gravity boots

src/p_mobj.c

@@ -2190,7 +2190,7 @@ void P_XYMovement(mobj_t *mo)
 
 			P_SlideMove(mo);
 			if (player)
-				mo->flags |= MF_SLIDEME;
+				player->powers[pw_pushing] = 3;
 			xmove = ymove = 0;
 
 #ifdef ESLOPE

src/p_user.c

@@ -9229,7 +9229,7 @@ void P_PlayerThink(player_t *player)
 	else if (cmd->forwardmove || cmd->sidemove) // only when you're pressing movement keys
 	{
 		if ((player->mo->movefactor < FRACUNIT) // hilarious absence of traction!
-		|| (player->mo->flags & MF_SLIDEME)
+		|| (player->powers[pw_pushing])
 		|| !(player->rmomx || player->rmomy)) // adjust to new angle
 			player->drawangle = player->mo->angle + R_PointToAngle2(0, 0, cmd->forwardmove<<FRACBITS, -cmd->sidemove<<FRACBITS);
 		else
@@ -9237,7 +9237,8 @@ void P_PlayerThink(player_t *player)
 	}
 
 
-	player->mo->flags &= ~MF_SLIDEME;
+	if (player->powers[pw_pushing])
+		player->powers[pw_pushing]--;
 	player->mo->movefactor = FRACUNIT; // We're not going to do any more with this, so let's change it back for the next frame.
 
 	// Unset statis flags after moving.