Renaming ng* modules to make the association with AngularJS clearer.
Moved all to com.asayama.gwt.angular group.

The com.asayama.gwt group will be used for other GWT utilities and
extensions in the future. Moved all the Angular stuff to angular
subgroup.
Moving all documentation projects to docs group

Having all the documentations and the API in the same Maven group made
it difficult to see what API was there. Separating them into different
Maven group.
Removed previous commented out dependency.