The CR in a macro definition line is now outputted as a space, in line with how CR is treated elsewhere in CPP. Adjusted testcase.
Simplify the code a bit by not having cls and tag as constants.
Touchups
RFC 6066 only allows one host DN in SNI.
Test extensions on selfsigned and root certs.
Nettle.BlockCipher16: Added new AEAD mode: EAX.

Test vectors from the EAX specification.

FIXME: Nettle only supports EAX with block ciphers having a 16 byte
block size. The actual specification supports any block size. Consider
implementing a generic version as well.

FIXME: Nettle also has an AES-specific implementation of EAX. Consider
adding support for it too.
Now that class and tag propagates, we don't have to make wrapper classes.