Should the block padding size validated?

[ulikunitz]

Thanks to Dórian C. Langbeck I realized that I confused the padding for the block header with the padding of the block in the discussion of issue #15 . Currently we don't check the block padding size. Whether we should check it is an open question.

3.3. Block Padding

        Block Padding MUST contain 0-3 null bytes to make the size of
        the Block a multiple of four bytes. This can be needed when
        the size of Compressed Data is not a multiple of four. If any
        of the bytes in Block Padding are not null bytes, the decoder
        MUST indicate an error.