Add LZ4 compression support.

- Add lz4 encoder to compress an image of type LZ4 (see spice_common).
- Add code in red_worker to use LZ4 when it is enabled, and the client
  supports it through its display capability, or fallback to LZ.
- Add enable_lz4 switch in the configure script. Show LZ4 support at the
  end.

1 files changed, 0 insertions, 0 deletions

diff --git a/spice-common b/spice-common
-Subproject b3a00f4411962e0c06c7ad89a9936df388aa002
+Subproject 5b3cdad921d32c9294377efac61243a09f849d0