Add Blosc plugin.

https://github.com/quixdb/squash/issues/32

Signed-off-by: Evan Nemerson <evan@coeus-group.com>
Fix potential segfault when finishing a stream w/o additional input.

Signed-off-by: Evan Nemerson <evan@coeus-group.com>
Silence some warnings from external code.

Signed-off-by: Evan Nemerson <evan@coeus-group.com>