Task lists WIP:

* initializing some code parts
* mechanism to add font-awesome icons to the defaults one that
  ConverseJS uses
* new way to override ConverseJS index.js (to add new custom plugins,
  that are directly build into ConverseJS)

conversejs/custom/plugins/tasks/utils.js

@@ -0,0 +1,32 @@
+import { _converse } from '../../../src/headless/core.js'
+import { __ } from 'i18n'
+
+export function getHeadingButtons (view, buttons) {
+  const muc = view.model
+  if (muc.get('type') !== _converse.CHATROOMS_TYPE) {
+    // only on MUC.
+    return buttons
+  }
+
+  const myself = muc.getOwnOccupant()
+  if (!myself || !myself.isModerator()) {
+    // User must be moderator
+    return buttons
+  }
+
+  // Adding a "Open task list" button.
+  buttons.unshift({
+    i18n_text: __('Tasks'),
+    handler: async (ev) => {
+      ev.preventDefault()
+      ev.stopPropagation()
+
+      // TODO.
+    },
+    a_class: '',
+    icon_class: 'fa-list', // FIXME
+    name: 'muc-tasks'
+  })
+
+  return buttons
+}