Compression strategy changes

* add Uncompressed option
* Use some of the inherent LZ4 compression/decompression bytebuffer stuff
LZ4FastDecompressor requires the size of the uncompressed data as the last argument to decompress,
vs. LZ4SafeDecompressor requires the maximum size of the output as the last argument, so we should only use lz4Fast if we know the size of the uncompressed data, which is not the case in this method.