Webrtc client side (#4026)

* WebRTC Server side

* WebRTC client side

* Bug fixes and improvements

* Pushing UI improvements for webrtc (#3728)

* Pushing UI improvements for webrtc

* Updating webrtc css

* PLT-3943 WebRTC P1: bug fixes and improvements

* Video resolution set to std, reduce volume of ringtone and flip video horizontally

* Fix calling a user B while WebRTC RHS is still opened

* Leave RHS opened when call ends, Fix isBusy on popover and channel_header

* Fix pre-release feature, RHS & System Console

* PLT-3945 - Updating UI for webrtc (#3908)

* PLT-3943 Webrtc p1

* Add ongoing call indicator when RHS is opened

* UI updates to to webrtc notifcation (#3959)

webapp/sass/utils/_variables.scss

@@ -17,3 +17,13 @@ $border-gray: 1px solid #ddd;
 
 // Random variables
 $border-rad: 1px;
+
+// Webrtc Variables
+$button--ready: #00A6EE;
+$video-circle-btn: #2f81b7;
+$video-circle-hover: #56C303;
+$video-circle-offline: #aaa;
+$button--cancel: #E41020;
+$button--pickup: #73B001;
+$connecting: $white;
+$webrtc-notification-bg: rgba(112, 128, 144, .8);