Add Practical introduction to ssl tls

[Hakky54]

Added an example project which has no security. It provides how-to steps to enable encryption with SSL/TLS for three scenarios:

• one way authentication - server communicates over https and identifies itself with a certificate
• two way authentication - both server and client needs to identify itself and trust each other
• two way authentication based on trusting the certificate authority - same as above one but trusting the root-ca is enough to get the same result

Java spring based web server A variation of http clients which are supported

Helps the person to learn about certificates, keystores, ssl commands and basic web security based on certificates.