Fridge: prefix panel layout tweak.

src/server/gwt/src/se/chalmers/cs/gf/gwt/client/FridgeBagPanel.java

@@ -31,6 +31,7 @@ public class FridgeBagPanel extends Composite {
 		this.pgf = pgf;
 		this.magnetFactory = magnetFactory;
 		prefixPanel = new FlowPanel();
+		prefixPanel.setStylePrimaryName("my-PrefixPanel");
 		mainPanel = new FlowPanel();
 		VerticalPanel vPanel = new VerticalPanel();
 		vPanel.setHorizontalAlignment(VerticalPanel.ALIGN_CENTER);

src/server/gwt/src/se/chalmers/cs/gf/gwt/public/Fridge.css

@@ -26,6 +26,10 @@ body {
   border: 3px solid #dddddd;
 }
 
+.my-PrefixPanel {
+  margin-bottom: 1em;
+}
+
 .my-Magnet {
   float: left;
   margin: 0.3em;