Add CTabFolder support to tests

The method verifyCompositeText in DialogCheck verifies various aspects
of composites, with
eclipse-platform/eclipse.platform.team#14 this
now needs to understand CTabFolder (in addition to TabFolder)

Also-by: Torbjörn Svensson <torbjorn.svensson@st.com>

tests/org.eclipse.ui.tests.harness/src/org/eclipse/ui/tests/harness/util/DialogCheck.java

@@ -20,6 +20,7 @@
 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.dialogs.IDialogConstants;
 import org.eclipse.swt.SWT;
+import org.eclipse.swt.custom.CTabFolder;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
@@ -122,6 +123,12 @@ private static void verifyCompositeText(Composite composite) {
 				for (int j = 0; j < numPages; j++) {
 					folder.setSelection(j);
 				}
+			} else if (child instanceof CTabFolder) {
+				CTabFolder folder = (CTabFolder) child;
+				int numPages = folder.getItemCount();
+				for (int j = 0; j < numPages; j++) {
+					folder.setSelection(j);
+				}
 			}
 			else if (child instanceof Button) {
 				//verify the text if the child is a button