Combine all CSS and JS resources of a page

CSS and JS resources are served bundle by bundle (each page specifies ~ 4 bundles), it would be better to be able to serve all the JS resources and all the CSS resources of a given page at once.

This requires adding a new wro servlet to serve these resources, and change the dependency between nuxeo-theme-styling and nuxeo-web-resources-wro (for now theme depends on resources-wro, but that should be the contrary for the wro model to be aware of the notion of page)

Behavior is controlled by a configuration property:

<component name="org.nuxeo.ecm.platform.webapp.base.properties">
  <extension target="org.nuxeo.runtime.ConfigurationService" point="configuration">
    <property name="nuxeo.jsf.combinePageResources">true</property>
  </extension>
</component>