*) will try other ports if YaCy standard ports are not available
*) distinguish between internal and external port (not sure if this
works 100%)
Still to add: propery in config to enter own external port (in case of
manually configured NAT)
besides adjustments in code it makes the servlet settings in web.xml significant.
This applies to solr, gsa and proxy servlet. There is no longer a default setup in code during init (as jetty 9 checks for double definition).
