Fix programming style
Change ENOTSUP -> EOPNOTSUPP

This change includes documentation update and transition to library
version 0.3.0
AEAD: AD send along with user data
convert _kcapi_common_getinfo to NETLINK_CRYPTO
deactivate _kcapi_common_getinfo

We need the kernel patch for crypto_user.c as outlined in TODO
v3 of kernel patch
v3 kernel patch: add cover letter
0.3.0: changelog added