- CustomBlockPlaceEvent now has the item that was used to place the block
- CustomBlockType#initialize should no longer return null if CustomBlockType#getCustom is not overridden
- DataBlock#set will now remove a key if null is passed, fixing an NPE with saving in the BlockDataManager
- Added a common filler constant to InventoryGUI
- Fixed bug with JSON parser that caused booleans to always evaluate to false
- Created RegionUtils and added a basic method to find interior space within a region