Diamond Pipes only drop item in first filter slot when broken #45

While messing around with SimplePipes in a test world, I noticed that a diamond pipe, when broken, either in creative or survival, did not drop the items I had put into its filter inventory. I looked through the source a little to find what could be causing this and I noticed in TilePipeItemDiamond.removeItemsForDrop() only removed/returned the item in the pipe's first inventory slot. I tested this in a world and found that the pipe indeed did drop any item placed in the first inventory slot but not in any other slots.

This is likely a simple fix. I can probably create a pull-request fixing this if necessary.