Critical security fix for embedded editor

git-svn-id: http://svg-edit.googlecode.com/svn/trunk@2723 eee81c28-f429-11dd-99c0-75d572ba1ddd
In case the frame changes location to an untrusted source such as via link click, the embedding API is now required to supply a list of any other origins that should be allowed.

git-svn-id: http://svg-edit.googlecode.com/svn/trunk@2724 eee81c28-f429-11dd-99c0-75d572ba1ddd