Add JavaDocs.
Add description support.
Support "coreFeature" property on Plugin, so UI can decide to not display a Remove button for core functionality.
Fix loading message key.
Add description.
Don't show a "Remove" button for core plugins.
Add description.
Tweak to better support allowing upgrade of normally-excluded bundles.
If an update to an excluded bundle is available, we return it so the UI
can allow users to upgrade it.
Tweaks to UI to handle display of plugins that are upgradable, but normally excluded from the available plugin list. This happens with lower level plugins, e.g. *.hw bundles, but the server will return them when an upgrade for them is available.