Added Ghost Item (like ghost tetronimos in tetris)

Play Screen:

1. Added Ghost Items
2. Added Dynamic Throw Line
3. Fixed Wall bug
   1. This was a bug that lets the player spam spawn items at the side of the screen
   2. I also fixed a bug last patch where items that collided would infinitely spawn more due to the odd amount of collisions that spawned extra items.  I made it so that there was an extra check to see if an item was in the middle of merging and made it so an item couldn't merge with a merging item. this however made it so that you can do double merges anymore. I might bring it back if it is wanted though
   3. double merges is where you have two items of the same type merge with a third item and spawn two new upgraded items instead of one. EX: two 1's plus a 1 dropped between them would make two 2's instead of one and they would combine to make a 4 resulting in a "Double Merge" or doop. haven't made a term for it yet...