Import from HNS - make arrays not mutable

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/simplewebkit/trunk@38154 72102866-910b-0410-8b05-ffd578937521
Import from HNS - signature change

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/simplewebkit/trunk@38155 72102866-910b-0410-8b05-ffd578937521