Reorganize test suite.

- Split testLoginLogout() into testBadLogin() and testLoginLogout().
- Mark testCreateSimpleArticle() as incomplete until the popup
  window opened by clicking on VIEW is handled correctly.
- Disable mod_rewrite so that the test suite does not depend on it.
- Remove superfluous check for Testing_Selenium class.
- Migrate TestConfiguration.php.dist to config.xml.dist.
  - Configure whitelist for code coverage information.
    - Be conservative for now and only add include/ and plugins/
      directories for now.
    - Set addUncoveredFilesFromWhitelist="false" because not all
      files are loadable (yet).
- Add documentation for code coverage reporting.

tests/coverage/phpunit_coverage.php

@@ -0,0 +1,36 @@
+<?php
+require_once 'PHPUnit/Util/FilterIterator.php';
+
+if (isset($_GET['PHPUNIT_SELENIUM_TEST_ID'])) {
+    $files = new PHPUnit_Util_FilterIterator(
+      new RecursiveIteratorIterator(
+        new RecursiveDirectoryIterator(dirname(__FILE__))
+      ),
+      '.phpunit_' . $_GET['PHPUNIT_SELENIUM_TEST_ID']
+    );
+
+    $coverage = array();
+
+    foreach ($files as $file) {
+        $filename = $file->getPathName();
+
+        $data = eval('return ' . file_get_contents($filename) . ';');
+        unset($filename);
+
+        foreach ($data as $filename => $lines) {
+            if (!isset($coverage[$filename])) {
+                $coverage[$filename] = $lines;
+            } else {
+                foreach ($lines as $line => $flag) {
+                    if (!isset($coverage[$filename][$line]) ||
+                        $flag > $coverage[$filename][$line]) {
+                        $coverage[$filename][$line] = $flag;
+                    }
+                }
+            }
+        }
+    }
+
+    var_export($coverage);
+}
+?>