Pause a preview when going on the main div

This reduce the CPU pressure, as only one stream needs to be decoded
Also prevent the main vid to double its audio level (which was not a bad thing, but was just beacause this same track was decoded and played twice, it'd be better to play with the volume of only one track)
Doesn't work well on FF for now (because FF doesn't like switching main div, it often do not resume the video, or after several seconds, will need to investigate)

public/js/vroom.js

@@ -356,6 +356,15 @@ function initVroom(room) {
     if ($('#mainVideo').html() != ''){
       $('#mainVideo').hide(200);
       wait = 200;
+      // Play all preview
+      // the one in the mainVid was paused, with a reduced opacity
+      // This isn't working on FF for the moment
+      if ($.browser.webkit){
+        $('#webRTCVideo video').each(function(){
+          $(this)[0].play();
+          $(this).css('opacity', '1');
+        });
+      }
     }
     setTimeout(function(){
       $('#mainVideo').html('');
@@ -376,6 +385,15 @@ function initVroom(room) {
         $('.selected').removeClass('selected');
         el.addClass('selected');
         mainVid = el.attr('id');
+        // Pause the corresponding preview
+        // and reduce opacity
+        if ($.browser.webkit){
+          $('#webRTCVideo video').each(function(){
+            $(this)[0].play();
+          });
+          el[0].pause();
+          el.css('opacity', '.3');
+        }
         $('#mainVideo').show(200);
       }
     }, wait);