* WiFiServerSecure: Cache the SSL sessions
* Add SSL session caching to HTTPS server examples
* Document server SSL session caching
* Fix an incomplete sentence in the documentation
* Document BearSSL::Session
* Use the number of sessions instead of the buffer size in ServerSessions' constructors
BearSSLX509List, BearSSLSession, BearSSLPublicKey, and BearSSLPrivateKey
were all in the global namespace and not in the BearSSL:: one, due to an
oversight when they were originally created. Move them to the proper
namespace with the following mapping:
BearSSLX509List => BearSSL::X509List
BearSSLSession => BearSSL::Session
BearSSLPublicKey => BearSSL::PublicKey
BearSSLPrivateKey => BearSSL::PrivateKey