fix an error in number input where it would validate for negative /
replace numbers when setIntegerValue was called.
add sound-packet.  No clue wtf to use those for, as I have no idea where
to get the sound-string names from.
lots more work on advaned spawner.  
add gui code to open and edit a block-based spawner.  
add fields to GUIs for block hardness  
cleanup some number-input default value assignment in spawner gui
lots more work on advanced spawner -- add 'rewards' inventory for when
block is broken / finished spawning.