[] (0) Simplify message ports: use queueing instead of transient 'active' functionality. Also, make localStorage use the same mechanism for obtaining origin as openDatabase().

git-svn-id: http://svn.whatwg.org/webapps@2023 340c8d12-0b0e-0410-8428-c7bf67bfef74

Author: Hixie