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
<contexts>
<context id="hoverHelpContext">
<description>Hover Help Guide</description>
<topic href="resources/help context/dl_hover/html/getting_started.html" label="Overview"/>
<topic href="resources/help context/dl_hover/html/setup.html" label="Set Up"/>
<topic href="resources/help context/dl_hover/html/preferences.html" label="Preferences"/>
</context>
</contexts>