Add support for syncing colors

// FREEBIE

js/background.js

@@ -136,6 +136,7 @@
             name: contactDetails.name,
             id: contactDetails.number,
             avatar: contactDetails.avatar,
+            color: contactDetails.color,
             type: 'private',
             active_at: Date.now()
         }).save();

js/models/conversations.js

@@ -355,7 +355,8 @@
         }
 
         var title = this.get('name');
-        var color;
+        var color = this.get('color');
+        if (!color) {
             if (this.isPrivate()) {
                 if (title) {
                     color = COLORS[Math.abs(this.hashCode()) % 15];
@@ -365,6 +366,7 @@
             } else {
                 color = 'default';
             }
+        }
 
         if (this.avatarUrl) {
             return { url: this.avatarUrl, color: color };

protos/IncomingPushMessageSignal.proto

@@ -109,4 +109,5 @@ message ContactDetails {
   optional string number = 1;
   optional string name   = 2;
   optional Avatar avatar = 3;
+  optional string color  = 4;
 }