[swgrrdul] Partial compression via recovery

Feed partial input to the compressor, yielding compressed output blocks.  Feed the compressed blocks to a decompressor, yielding a prefix of the partial input.  The missing suffix represents the unfinished last block.

The decompressor should operate in an aggressive mode that outputs every byte as soon as it is available, not holding on to bytes for buffering, not waiting for the final "flush" block which will never come.  Perhaps some sort of recovery mode.

This was a half-baked idea, continuing thoughts on appendable compression without loss of efficiency (asymptotically).