Move GWT-RPC objects to shared package (where they should be).

Move GWT-RPC objects to shared package (where they should be).

* src/main/java/org/glom/web/client/LibGlomService.java: Update imports.
* src/main/java/org/glom/web/client/LibGlomServiceAsync.java: Update imports.
* src/main/java/org/glom/web/client/OnlineGlom.java: Update imports.
* src/main/java/org/glom/web/server/LibGlomServiceImpl.java: Update imports.
* src/main/java/org/glom/web/shared/GlomDocument.java: Move to
org.glom.web.shared package.
* src/main/java/org/glom/web/shared/GlomTable.java: Move to
org.glom.web.shared package.
* src/main/resources/org/glom/web/OnlineGlom.gwt.xml: Included shared
directory in compilation to javascript.