Use C99.

We were already depending on some C99 features.  Let's just make it
official so we can start mixing code and variable declarations (along
with some other nice things).

Signed-off-by: Evan Nemerson <evan@coeus-group.com>
Add Intel Performance Primitives plugin.

Currently, this plugin only implements the lzo1x codec.  It should be
possible to implement bzip2, deflate, zlib, gzip, and possibly other
codecs, but AFAICT this would require significant effort and/or using
deprecated API.

Signed-off-by: Evan Nemerson <evan@coeus-group.com>
docs: Update for doxygen-1.8.5

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