Suggestion to fix water farming issue

Added an onBlockFromTo event handler to check for water flowing over crop blocks.

Code also manually replaces the block with AIR to prevent normal items from dropping, and then we drop the new regulated amount, which in this case is either 1 wheat or 1 seed depending on what stage the crop block is at.

This way we can have it manual farming is more rewarding but water farming is quicker (for breaking crops at least...)