Breaking a block drops the same item you used to place it.
When a block is placed and the item that player used to place have NBT,
we save the item to the block (actually in the chunk data).
I won't be very active on this project (as this is a free resource),
so there might be bugs or something wrong.
You can submit an issue to request feature or report bug.
I'll take a look when I'm free.
You can't compile from the source code directly,
this source code is mainly for review.
If you have experience with maven, you will know what to do to make it build.