- Delete spent TX in setclearSpentData when unspent by block
disconnect on reorg; return an error when there's more than
one record to delete in the spent TX as that should never
happen.
- Test spent TX deletion when reorg causes block disconnect.
- Test for correct NewestSha results after DropAfterBlockBySha.
- Fix DropAfterBlockBySha to update info for NewestSha.
- Updated copyright statements in modified files
