Review ssl-config-akka scope

[jrudolph]

It seems there's still "common" functionality in ssl-config-akka:

• everything related to SSLEngineConfigurator
• validateDefaultTrustManager
• configureProtocols
• configureCipherSuites

These seem to be only in there because they want to log. It might make sense to either abstract logging or just use slf4j directly and then move / unify that with ssl-config.

Also, looseDisableSNI seems to operate both on client and server settings which doesn't make much sense (and the warning is probably inaccurate / wrong).