Fix the case where Brotli doesn't consume all input.

[rdblue]

The JNI wrapper in C++ currently assumes that Brotli consumes all of the available bytes in the input buffer, but this isn't always the case. Brotli will sometimes leave the in_available value less than the number of bytes available, which causes jbrotli to discard some unprocessed input bytes and fail decompression.

This patch adds BrotliStreamDeCompressorResult to return the error code, bytes consumed, and bytes produced by the stream decompressor and correctly updates the ByteBuffer handling in Java to correctly track what of the input buffer was consumed (so it can be passed into Brotli again to consume the rest). Using a Java class also avoids packing and unpacking the return value.

[nitram509]

Ryan, thank you very much for pointing this out and making this PR.
It looks great and I will merge it.

Regarding some of your changes, I just have some minor comments.
Which means no show stopper, but e.g. I don't want to have a 'todo' in the code base ;-)

[nitram509]

Very good idea to replace the bit-twiddling error handling with such an Object.

[rdblue]

Thanks for merging this! I've also opened #4 because we can't currently use the published jar on either dev or prod systems because of the version of C++ used. Using 4.8 will make this more portable and would be good to switch to for the next release with this PR included. Thanks @nitram509!