Add a new PubKey class to handle public key signature verification. The
implementation is based on the gnutls library, which is added as an
optional dependency. If gnutls is not found, signature verification will
unconditionally fail.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
