frontend: Introduce GinUiBinder

Added support for the GinUiBinder feature of GWTP 1.3.
GinUiBinder replaces the standard GWT UiBinder with GTWP's implementation
adding support for injecting GIN dependencies into views created by UiBinder.

This can be greately beneficial in many cases where we use @UiField(provided=true)
just to pass dependencies to child views.

In order to create GIN-enabled view, just use @Inject annotated constructor
where you inject required dependencies (you can also inject editor Driver and
IdHandler instead of GWT.create-ing them) and add method returning type of your view to the
apropriate GinUiBinderWidgets ginjector extension.

The ginjector extensions for respective modules are:
 * gwt-common: CommonGinUiBinderWidgets
 * webadmin: WebAdminGinUiBinderWidgets
 * userportal-gwtp: UserPortalGinUiBinderWidgets

Change-Id: Ib3ac93ae3c8a80f5b49a0780ed8c9a674a109779
Signed-off-by: Martin Betak <mbetak@redhat.com>