More portal framework changes:
support for page command bars in page extension
ordering across layers on page
abstract discovery UI pages
improvements to open editor asap and defer updates if needed
<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.2"?>
<plugin>
<extension-point id="featureUseTracker" name="Feature Usage Tracker" schema="schema/featureUseTracker.exsd"/>
</plugin>