Move some background modules to a separate folder and fix init order

ext/src/background/receiverSelector/ReceiverSelector.ts

@@ -0,0 +1,37 @@
+"use strict";
+
+import { TypedEventTarget } from "../../lib/typedEvents";
+import { Receiver } from "../../types";
+
+
+export enum ReceiverSelectorMediaType {
+    App = 1
+  , Tab = 2
+  , Screen = 4
+  , File = 8
+}
+
+export interface ReceiverSelection {
+    receiver: Receiver;
+    mediaType: ReceiverSelectorMediaType;
+    filePath?: string;
+}
+
+
+export interface ReceiverSelectorEvents {
+    "selected": ReceiverSelection;
+    "error": void;
+    "cancelled": void;
+}
+
+export default interface ReceiverSelector
+        extends TypedEventTarget<ReceiverSelectorEvents> {
+
+    readonly isOpen: boolean;
+
+    open (receivers: Receiver[]
+        , defaultMediaType: ReceiverSelectorMediaType
+        , availableMediaTypes: ReceiverSelectorMediaType): void;
+
+    close (): void;
+}