fix(ngModel): use paste/cut events in IE to support context menu

In IE the model is not updated when the input value is modified using the context
menu, e.g. pasting from the clipboard, or cutting all or part of the current value.
To capture these changes, we bind to the proprietary 'paste' and 'cut' events.

Closes angular#1462

Author: markdalgleish

src/ng/directive/input.js

@@ -413,23 +413,32 @@ function textInputType(scope, element, attr, ctrl, $sniffer, $browser) {
   } else {
     var timeout;
 
+    var deferListener = function() {
+      if (!timeout) {
+        timeout = $browser.defer(function() {
+          listener();
+          timeout = null;
+        });
+      }
+    };
+
     element.bind('keydown', function(event) {
       var key = event.keyCode;
 
       // ignore
       //    command            modifiers                   arrows
       if (key === 91 || (15 < key && key < 19) || (37 <= key && key <= 40)) return;
 
-      if (!timeout) {
-        timeout = $browser.defer(function() {
-          listener();
-          timeout = null;
-        });
-      }
+      deferListener();
     });
 
     // if user paste into input using mouse, we need "change" event to catch it
     element.bind('change', listener);
+
+    // if user modifies input value using context menu in IE, we need "paste" and "cut" events to catch it
+    if ($sniffer.hasEvent('paste')) {
+      element.bind('paste cut', deferListener);
+    }
   }