explicitly run garbage collector when exchanging the BoxWidget instance

Signed-off-by: Florian Thienel <florian@thienel.org>
diff --git a/org.eclipse.vex.ui/src/org/eclipse/vex/ui/boxview/RefreshHandler.java b/org.eclipse.vex.ui/src/org/eclipse/vex/ui/boxview/RefreshHandler.java
index 9ab715e..27853b4 100644
--- a/org.eclipse.vex.ui/src/org/eclipse/vex/ui/boxview/RefreshHandler.java
+++ b/org.eclipse.vex.ui/src/org/eclipse/vex/ui/boxview/RefreshHandler.java
@@ -12,6 +12,7 @@
 	public Object execute(final ExecutionEvent event) throws ExecutionException {
 		final BoxView boxView = (BoxView) ((IEvaluationContext) event.getApplicationContext()).getVariable(ISources.ACTIVE_PART_NAME);
 		boxView.refresh();
+		System.gc();
 
 		return null;
 	}