Revert to explicit Promise-based code.

* src/converse-controlbox.js

    async/await causes many tests here to fail due to the controlbox toggle
    now apparently showing up a little later (and the tests don't wait for
    it to happen).

* src/converse-minimize.js

    We get timeout issues in tests.

* src/headless/converse-chatboxes.js

    We get a stack overflow while running tests.

src/converse-controlbox.js

@@ -154,7 +154,7 @@ converse.plugins.add('converse-controlbox', {
         }
     },
 
-    async initialize () {
+    initialize () {
         /* The initialize function gets called as soon as the plugin is
          * loaded by converse.js's plugin machinery.
          */
@@ -238,13 +238,14 @@ converse.plugins.add('converse-controlbox', {
                 }
             },
 
-            async insertRoster () {
+            insertRoster () {
                 if (_converse.authentication === _converse.ANONYMOUS) {
                     return;
                 }
                 /* Place the rosterview inside the "Contacts" panel. */
-                await _converse.api.waitUntil('rosterViewInitialized');
-                this.controlbox_pane.el.insertAdjacentElement('beforeEnd', _converse.rosterview.el);
+                _converse.api.waitUntil('rosterViewInitialized')
+                    .then(() => this.controlbox_pane.el.insertAdjacentElement('beforeEnd', _converse.rosterview.el))
+                    .catch(_.partial(_converse.log, _, Strophe.LogLevel.FATAL));
             },
 
              createBrandHeadingHTML () {
@@ -505,10 +506,11 @@ converse.plugins.add('converse-controlbox', {
                 'href': "#"
             },
 
-            async initialize () {
+            initialize () {
                 _converse.chatboxviews.insertRowColumn(this.render().el);
-                await _converse.api.waitUntil('initialized');
-                this.render.bind(this);
+                _converse.api.waitUntil('initialized')
+                    .then(this.render.bind(this))
+                    .catch(_.partial(_converse.log, _, Strophe.LogLevel.FATAL));
             },
 
             render () {
@@ -587,11 +589,10 @@ converse.plugins.add('converse-controlbox', {
             }
         });
 
-        await Promise.all([
+        Promise.all([
             _converse.api.waitUntil('connectionInitialized'),
             _converse.api.waitUntil('chatBoxViewsInitialized')
-        ]);
-        _converse.addControlBox();
+        ]).then(_converse.addControlBox).catch(_.partial(_converse.log, _, Strophe.LogLevel.FATAL));
 
         _converse.on('chatBoxesFetched', () => {
             const controlbox = _converse.chatboxes.get('controlbox') || _converse.addControlBox();

src/converse-minimize.js

@@ -299,7 +299,7 @@ converse.plugins.add('converse-minimize', {
     },
 
 
-    async initialize () {
+    initialize () {
         /* The initialize function gets called as soon as the plugin is
          * loaded by Converse.js's plugin machinery.
          */
@@ -509,12 +509,16 @@ converse.plugins.add('converse-minimize', {
             }
         });
 
-        await _converse.api.waitUntil('connectionInitialized');
-        await _converse.api.waitUntil('chatBoxViewsInitialized');
+        Promise.all([
+            _converse.api.waitUntil('connectionInitialized'),
+            _converse.api.waitUntil('chatBoxViewsInitialized')
+        ]).then(() => {
             _converse.minimized_chats = new _converse.MinimizedChats({
                 model: _converse.chatboxes
             });
             _converse.emit('minimizedChatsInitialized');
+        }).catch(_.partial(_converse.log, _, Strophe.LogLevel.FATAL));
+
 
         _converse.on('registeredGlobalEventHandlers', function () {
             window.addEventListener("resize", _.debounce(function (ev) {

src/headless/converse-chatboxes.js

@@ -653,7 +653,7 @@ converse.plugins.add('converse-chatboxes', {
                 }
             },
 
-            async onMessage (stanza) {
+            onMessage (stanza) {
                 /* Handler method for all incoming single-user chat "message"
                  * stanzas.
                  *
@@ -727,8 +727,9 @@ converse.plugins.add('converse-chatboxes', {
                           message = msgid && chatbox.messages.findWhere({msgid});
                     if (!message) {
                         // Only create the message when we're sure it's not a duplicate
-                        const msg = await chatbox.createMessage(stanza, original_stanza);
-                        chatbox.incrementUnreadMsgCounter(msg);
+                        chatbox.createMessage(stanza, original_stanza)
+                            .then(msg => chatbox.incrementUnreadMsgCounter(msg))
+                            .catch(_.partial(_converse.log, _, Strophe.LogLevel.FATAL));
                     }
                 }
                 _converse.emit('message', {'stanza': original_stanza, 'chatbox': chatbox});