+ minor updates for
[2.3.x] Changes for https://java.net/jira/browse/GRIZZLY-1603 (Make HTTP Host header parsing lazy).
[2.3.x] + implement improvement #1609
https://java.net/jira/browse/GRIZZLY-1609

"Optimize HTTP mapping logic for the case, when only one root HttpHandler is registered"
[2.3.x] + fix copyright header