Doubled the amount of money pickups give you in "original" difficulty.

This is to compensate for the loss of the money bonus that used to
be there, to make the money you get more or less the same as in
version 1.2.

src/game.cpp

@@ -203,6 +203,9 @@ static void game_doCollectables()
 				switch(collectable->type)
 				{
 					case P_CASH:
+						if (currentGame.difficulty == DIFFICULTY_ORIGINAL)
+							collectable->value *= 2;
+
 						currentGame.cash += collectable->value;
 						currentGame.cashEarned += collectable->value;
 						sprintf(temp, "Got $%d ", collectable->value);