Add window zoom menu item (#325)

* Move window close button into shell submenu

IMO actions that affect a session don't belong into the window menu.

* Add window zoom menu item

fixes #234

menu.js

@@ -87,6 +87,11 @@ module.exports = function createMenu ({ createWindow, updatePlugins }) {
               focusedWindow.rpc.emit('session close req');
             }
           }
+        },
+        {
+          label: 'Close Terminal Window',
+          role: 'close',
+          accelerator: 'CmdOrCtrl+Shift+W',
         }
       ]
     },
@@ -209,7 +214,7 @@ module.exports = function createMenu ({ createWindow, updatePlugins }) {
           role: 'minimize'
         },
         {
-          role: 'close'
+          role: 'zoom'
         },
         {
           type: 'separator'