Issue 2148 - Rewrite the testpages test suite

pages/exceptions/xmlhttprequest.tmpl

 title = $xmlhttprequest Exception
+template = testcase
 
 {% set testcase_moreinfo = [
   ("Filter Options", "https://adblockplus.org/filters#options"),
 ] %}
 
 <script>
-function pagelog(message) {
-  var log = document.getElementById("testcase-ex-xmlhttprequest");
-  log.innerText = log.innerText + message + "\n";
-  console.log(message);
-}
-
 function aborted(evt) {
   pagelog("XMLHTTPRequest was aborted.");
 }
 
 function failed(evt) {
   pagelog("XMLHTTPRequest failed.");
 }
 
 function makerequest() {
   var req = new XMLHttpRequest();
@@ skipping 15 matching lines @@
   <h2>$xmlhttprequest Exception</h2>
   <p>Check that usage of the $xmlhttprequest filter option in an exception filter works as expected.</p>
   <p>With the filter(s) displayed below each test case added to ABP (or with the testcase subscription installed and active), the XMLHTTPRequest should not be blocked while the image should be.</p>
 </section>
 
 <section class="site-panel">
   <h2>Test case</h2>
   <p>The XMLHTTPRequest should not be blocked. The Image should be blocked.</p>
   <div class="testcase-container">
     <div class="testcase-row">
-      <h3>XMLHTTPRequest</h3><div id="testcase-ex-xmlhttprequest"></div>
+      <h3>XMLHTTPRequest</h3><div id="testcase-output"></div>
     </div>
     <div class="testcase-row">
       <h3>Image</h3><img class="testcase-image" src="/testcasefiles/xmlhttprequestexception/image.jpg"/>
     </div>
   </div>
   <h3>Filters</h3>
   <pre>||testpages.adblockplus.org/testcasefiles/xmlhttprequestexception/*</pre>
   <pre>@@testpages.adblockplus.org/testcasefiles/xmlhttprequestexception/$xmlhttprequest</pre>
 </section>