Adds a config param startSilent to disable audio output.

conference.js

                     this.recorder = new Recorder();
                 }
 
+                if (config.startSilent) {
+                    APP.store.dispatch(showNotification({
+                        descriptionKey: 'notify.startSilentDescription',
+                        titleKey: 'notify.startSilentTitle'
+                    }));
+                }
+
                 // XXX The API will take care of disconnecting from the XMPP
                 // server (and, thus, leaving the room) on unload.
                 return new Promise((resolve, reject) => {

config.js

     // applied locally. FIXME: having these 2 options is confusing.
     // startWithAudioMuted: false,
 
+    // Enabling it (with #params) will disable local audio output of remote
+    // participants and to enable it back a reload is needed.
+    // startSilent: false
+
     // Video
 
     // Sets the preferred resolution (height) for local video. Defaults to 720.

lang/main.json

         "mutedTitle": "You're muted!",
         "raisedHand": "__name__ would like to speak.",
         "somebody": "Somebody",
+        "startSilentTitle": "You joined with no audio output!",
+        "startSilentDescription": "Rejoin the meeting to enable audio",
         "suboptimalExperienceDescription": "Eer... we are afraid your experience with __appName__ isn't going to be that great here. We are looking for ways to improve this but, until then, please try using one of the <a href='static/recommendedBrowsers.html' target='_blank'>fully supported browsers</a>.",
         "suboptimalExperienceTitle": "Browser Warning",
         "newDeviceCameraTitle": "New camera detected",

modules/UI/videolayout/SmallVideo.js

-/* global $, APP, interfaceConfig */
+/* global $, APP, config, interfaceConfig */
 
 /* eslint-disable no-unused-vars */
 import React from 'react';
 
     if (isVideo) {
         element.setAttribute('muted', 'true');
+    } else if (config.startSilent) {
+        element.muted = true;
     }
 
     element.autoplay = true;

react/features/base/config/functions.any.js

     'startAudioMuted',
     'startAudioOnly',
     'startBitrate',
+    'startSilent',
     'startScreenSharing',
     'startVideoMuted',
     'startWithAudioMuted',