Initiates SSL session.
This method causes TElSSLClient to initiate
SSL handshake. Call this method after transport has established
If SSL is not enabled (Enabled property is set to false), TElSSLClient does nothing and returns immediately.
The method is asynhronous and after it's return the SSL session is not yet established. If SSL is enabled, the application should call DataAvaialble in loop until either Active property becomes True or error happens (the application is notified about an error via OnError event). See samples for more details.