Add KeyboardDelegate.

Evergreen/MainWindow/KeyboardDelegateProtocol.swift

@@ -0,0 +1,17 @@
+//
+//  KeyboardDelegateProtocol.swift
+//  Evergreen
+//
+//  Created by Brent Simmons on 10/11/16.
+//  Copyright © 2016 Ranchero Software. All rights reserved.
+//
+
+import Cocoa
+
+let keypadEnter: unichar = 3
+
+protocol KeyboardDelegate: class {
+	
+	// Return true if handled.
+	func handleKeydownEvent(_: NSEvent, sender: AnyObject) -> Bool
+}