Loads of changes that are tightly connected... :/
* Change lambdas to static functions
* Add spec docs to those functions
* Keep the current scope around as a parameter
* Add wrapping classes for some Certificate members
* Parse ec and ecdsa data from certificates
With this change the certificate chain sent by the server will actually
be verified, instead of just checking the names of the certificates.
To determine if a certificate is signed by a root certificate, the list
of root certificates is now a HashMap mapping from the unique identifier
string to the certificate. This allows us to take the issuer of a
certificate and easily check if it is a root certificate. If a
certificate is not signed by a root certificate, we will check that it
is signed by the next certificate in the chain.
This also removes the ad-hoc checking of certificate validity from
multiple places, and moves all checking to the verify_chain.
