MDL-44070 Conditional availability enhancements (6): core changes

Changes core code to use new API instead of the old one when
checking user access to activities and sections.

Includes changes to other libraries that are necessary after
adding the availability system and removing old conditional tables
etc.

lib/testing/generator/module_generator.php

@@ -176,7 +176,7 @@ abstract class testing_module_generator extends component_generator_base {
         $easymergefields = array('section', 'added', 'score', 'indent',
             'visible', 'visibleold', 'groupmode', 'groupingid', 'groupmembersonly',
             'completion', 'completiongradeitemnumber', 'completionview', 'completionexpected',
-            'availablefrom', 'availableuntil', 'showavailability', 'showdescription');
+            'availability', 'showdescription');
         foreach ($easymergefields as $key) {
             if (isset($options[$key])) {
                 $moduleinfo->$key = $options[$key];
@@ -191,9 +191,7 @@ abstract class testing_module_generator extends component_generator_base {
             'groupmode' => 0,
             'groupingid' => 0,
             'groupmembersonly' => 0,
-            'showavailability' => 0,
-            'availablefrom' => 0,
-            'availableuntil' => 0,
+            'availability' => null,
             'completion' => 0,
             'completionview' => 0,
             'completionexpected' => 0,