MDL-43856 MathJax: Improvements to the MathJax filter

* Remove all traces of mathjax from the atto equation editor - it is filter agnostic
* Add a M.core.event module for core events that can be published/subscribed to by plugins (loose coupling)
* Add a FILTER_CONTENT_UPDATED event so plugins can tell the filter system when nodes are added to the page
* Implement a listener for this event in the MathJax filter
* Fire this event from the equation editor and from the glossary filter
* Add a nolink tag to the mathjax filter, so equations will not be processed by the other filters
* Add a smarter throttle function to the equation editor preview updates (Y.throttle is dumb)

filter/mathjaxloader/settings.php

@@ -44,6 +44,12 @@ if ($ADMIN->fulltree) {
                                          PARAM_RAW);
     $settings->add($item);
 
+    $item = new admin_setting_configcheckbox('filter_mathjaxloader/texfiltercompatibility',
+                                         new lang_string('texfiltercompatibility', 'filter_mathjaxloader'),
+                                         new lang_string('texfiltercompatibility_help', 'filter_mathjaxloader'),
+                                         0);
+    $settings->add($item);
+
     $default = '
 MathJax.Hub.Config({
     config: ["MMLorHTML.js", "Safe.js"],
@@ -58,19 +64,6 @@ MathJax.Hub.Config({
         mpMouse: true
     },
     errorSettings: { message: ["!"] },
-    tex2jax: {
-        skipTags: ["script","noscript","style","textarea"],
-        inlineMath: [
-            ["\\\\(","\\\\)"],
-            ["$$","$$"],
-            ["\\\\[","\\\\]"]
-        ],
-        displayMath: [
-            ["[tex]","[/tex]"],
-        ],
-        balanceBraces: true,
-        preview: "TeX"
-    },
     skipStartupTypeset: true,
     messageStyle: "none"
 });