Implemented test of cell offsets as test case for HtmlUnit bug.

+package pl.labno.bernard.htmlunified;
+
+import com.gargoylesoftware.htmlunit.BrowserVersion;
+import com.gargoylesoftware.htmlunit.CollectingAlertHandler;
+import com.gargoylesoftware.htmlunit.WebClient;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.IOException;
+
+public class TableCellOffsetTest {
+
+    @Test
+    public void testClickImage() throws IOException {
+        final WebClient client = new WebClient(BrowserVersion.FIREFOX_3_6);
+        CollectingAlertHandler collectingAlertHandler = new CollectingAlertHandler();
+        client.setAlertHandler(collectingAlertHandler);
+        client.getPage("file:./target/test-classes/tableCellOffset.html");
+        for (String message : collectingAlertHandler.getCollectedAlerts()) {
+            Assert.assertTrue("Comparison of rows offset().left returned false", Boolean.parseBoolean(message));
+        }
+    }
+
+}