add initial support for viewing variants in the sdk config tree. refactor some code which initializes sbsv2 contexts.
some hacks added for re-loading configurations when the default config is a variant.
<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>