Remember volume settings between streams

This is same-session only. We still don't store any session data or
cookies. We dump mute and volume settings to an object when a webcall
stream is reaped, then restore them if the stream comes back.

This should address hardship in a lossy connection or someone
"quickly restarting OBS" needing to re-unmute the player.

Closes #5

assets/player.js

@@ -7,6 +7,7 @@ xhr.onreadystatechange = function() {
 }
 
 disabledPlayers = [];
+playerVolumeSettings = {};
 
 // Auto-resize frames in a webcall interface
 function webcallFrameResize() {
@@ -146,8 +147,12 @@ function closePlayer(containerId) {
 }
 
 function destroyPlayerById(containerId) {
-  // Tear down player
   player = OvenPlayer.getPlayerByContainerId(containerId);
+
+  // Get our volume settings to save for re-use if this player comes back
+  playerVolumeSettings[containerId] = [player.getMute(), player.getVolume()];
+
+  // Tear down player
   player.remove();
 
   // Delete frame
@@ -171,7 +176,16 @@ function processStreamList(streams) {
   // Create any player in the list that doesn't have one
   streams.forEach((i, index) => {
     if (OvenPlayer.getPlayerByContainerId(i) == null) {
-      createPlayer(i, true, 100);
+      // Check if we have volume settings for this player
+      var muted = true;
+      var volume = 100;
+      if (i in playerVolumeSettings) {
+        muted = playerVolumeSettings[i][0];
+        volume = playerVolumeSettings[i][1];
+      }
+
+      // Create the player with noted settings or defaults
+      createPlayer(i, muted, volume);
     }
   })