416015 Handle null Accept-Language and other headers
Merge remote-tracking branch 'origin/master' into jetty-9.1

Conflicts:
	jetty-server/src/test/java/org/eclipse/jetty/server/RequestTest.java
416015 Handle null Accept-Language and other headers
Merge branch 'jetty-9.1' of ssh://git.eclipse.org/gitroot/jetty/org.eclipse.jetty.project into jetty-9.1