fix the circular dependencies from provisional.dom to internal.dom

Change-Id: I5b739faaa94088b0607d54446060f7414f665120
Signed-off-by: Florian Thienel <florian@thienel.org>
diff --git a/org.eclipse.vex.core/src/org/eclipse/vex/core/provisional/dom/IIncludeNode.java b/org.eclipse.vex.core/src/org/eclipse/vex/core/provisional/dom/IIncludeNode.java
index 1cdf7c4..27c6c60 100644
--- a/org.eclipse.vex.core/src/org/eclipse/vex/core/provisional/dom/IIncludeNode.java
+++ b/org.eclipse.vex.core/src/org/eclipse/vex/core/provisional/dom/IIncludeNode.java
@@ -10,8 +10,6 @@
  *******************************************************************************/
 package org.eclipse.vex.core.provisional.dom;
 
-import org.eclipse.vex.core.internal.dom.Element;
-
 /**
  * A representation of an XML element that includes content.
  */
@@ -19,7 +17,7 @@
 	/**
 	 * @return The Element that defines this include in the source document.
 	 */
-	public Element getReference();
+	public IElement getReference();
 
 	INode getResolved();