Bug 40788 [plan item] Configurable Next/Previous actions
Toolbar drop down, or editor specific control. Needs to be coordinated with Platform UI.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/JavaPlugin.java
static IPath getInstallLocation() {
		return new Path(getDefault().getDescriptor().getInstallURL().getFile());
	}
	
	public static ImageDescriptorRegistry getImageDescriptorRegistry() {
		return getDefault().internalGetImageDescriptorRegistry();
	}
	
	public JavaPlugin(IPluginDescriptor descriptor) {
		super(descriptor);
		fgJavaPlugin= this;
	}
	/* (non - Javadoc)
	 * Method declared in Plugin
	 */
	public void startup() throws CoreException {
		super.startup();
		registerAdapters();
		
		if (USE_WORKING_COPY_OWNERS)
			DefaultWorkingCopyOwner.PRIMARY.factory= new CustomBufferFactory();
		/*
		 * Backward compatibility: propagate the Java editor font from a
		 * pre-2.1 plug-in to the Platform UI's preference store to preserve
		 * the Java editor font from a pre-2.1 workspace. This is done only
		 * once.
		 */
		String fontPropagatedKey= "fontPropagated"; 
		if (getPreferenceStore().contains(JFaceResources.TEXT_FONT) && !getPreferenceStore().isDefault(JFaceResources.TEXT_FONT)) {
			if (!getPreferenceStore().getBoolean(fontPropagatedKey))