Bug 362532 - [CSS] Re-enable dynamic CSS pseudo-classes

Enable dynamic pseudo-classes when org.eclipse.e4.ui.css.dynamic system
property is true.  Defaults to false.
diff --git a/bundles/org.eclipse.e4.ui.css.swt/src/org/eclipse/e4/ui/css/swt/dom/WidgetElement.java b/bundles/org.eclipse.e4.ui.css.swt/src/org/eclipse/e4/ui/css/swt/dom/WidgetElement.java
index 0201491..8ab9f58 100644
--- a/bundles/org.eclipse.e4.ui.css.swt/src/org/eclipse/e4/ui/css/swt/dom/WidgetElement.java
+++ b/bundles/org.eclipse.e4.ui.css.swt/src/org/eclipse/e4/ui/css/swt/dom/WidgetElement.java
@@ -28,7 +28,8 @@
  */
 public class WidgetElement extends ElementAdapter implements NodeList {
 	
-	boolean dynamicEnabled = false;
+	boolean dynamicEnabled = Boolean
+			.getBoolean("org.eclipse.e4.ui.css.dynamic");
 	
 	/**
 	 * Convenience method for getting the CSS class of a widget.