Parser.HTML: overlap in arguments to MEMCPY
SSL.sslport: Changed API.

To allow SSL configuration via overloading of symbols in SSL.context,
SSL.sslport and SSL.https no longer inherit SSL.context. Instead
they now have an explicit SSL.context object that is passed along
to SSL.sslfile.

Also adds corresponding compat classes.
SSL.context: Added alert_factory().
SSL.connection: Use context->alert_factory().

SSL.handshake and SSL.connection now use the alert factory to
create all alerts. This allows for customized logging of alerts.

Also cleans up quite a few alert messages to have more information
than just the description code, or remove some redundant info.
SSL.https: Log all alerts.
Crypto.ECC: Support SHA1 for signatures.

ECDSA/SHA1 signatures is the default combination to support for
ECDSA certificates in TLS 1.2 if the client hasn't said otherwise.
Gmp: size() always returns positive.
Crypto.DSA: Added key_size().
version is in the variable scope.
__builtin.Nettle.Sign: Added key_size().