update interface with a new direction
update license file.
speedup AES GCM context copy by splitting apart immutable (aes key) and
mutable part (gcm context).
remove commented import list
move to a branching table, and add more consistent api.
add basic support for AES256 with AESNI
add support for block with a 256 bits keys through AESNI.

massive speedup for CTR/XTS/GCM