My original implementation had options to both include as well as exclude specific
encryption protocols and cipher suites. This proved to be to much - Configuration
becomes a nightmare and setups ended up with having no enabled suites at all. This
commit simplifies things: a connection listener now gets a list of protocols and
suites that are enabled - that's it. When no setting is provided, the JVM default
is used (which itself is tweakable through generic Java configuration revolving
around the file JRE_HOME/lib/security/java.security )