Make GQ server side not depends on gwt-servlet not gwt-dev

Adding org.json dependency since we depend on it, and 2.7
uses a rebased version of android.json. We will have this
dependency in snapshot until we replace json usage in server
side, but we have to remove before releasing gquery.
Just one concern here: Are you sure this test is reliable ? I mean a lot of people doesn't know how to manage correctly dependencies with maven and the GWT jar files can be deployed on server side.