Improve SSL performance by limiting SSL message size

• with TLS (how about SSL v3?), calls to ssl_write should be at most 1200 bytes (apparently one call to ssl_write will trigger one message to be sent)
• bigger chunks would cause one message to be sent in several TCP packets
• The server then would need to wait until all TCP packets have been received until it can decrypt the message.

The goal is to use SSL so we create encrypted packets that are <= MTU.