Bug 154100 Platform level proxy settings
There are at least three proxy settings pages in Callisto. We will work with the Eclipse community to make sure that the core capabilities from these pages are made available at the Platform level, as a single settings page that can be consumed by all. [Runtime, Team, Update, UI]
bundles/org.eclipse.ui.ide.application/src/org/eclipse/ui/internal/ide/application/IDEWorkbenchAdvisor.java
private static final String WORKBENCH_PREFERENCE_CATEGORY_ID = "org.eclipse.ui.preferencePages.Workbench"; 
	/**
	 * The dialog setting key to access the known installed features since the
	 * last time the workbench was run.
	 */
	private static final String INSTALLED_FEATURES = "installedFeatures"; 
	private static IDEWorkbenchAdvisor workbenchAdvisor = null;
	/**
	 * Contains the workspace location if the -showlocation command line
	 * argument is specified, or <code>null</code> if not specified.
	 */
	private String workspaceLocation = null;
	/**
	 * Ordered map of versioned feature ids -> info that are new for this