CCM Authentication optimization

CCM   is now optimized. Instead of being computed twice,
libtomcrypt code has been optimized so that classical ccm_init, ccm_process,...
can be used incrementally (when the whole stream is not available when
starting the authentication).
CCM way of proceeding is now very closed to GCM authentication.
ccm_init() updates the taglen (make it even and less than 16). So this leads in error when testing.

In ccm_init, I did not want to return an error in tag_len is not ok to keep coherency with respect to ccm_memory.