Slight grab-bag of fixes for electron on Windows

* Implement the squirrel install / uninstall hooks (so we have
   a start menu entry / desktop shortcut)
 * Wait longer before checking for update
 * Set the window icon
 * Add a 'file' menu
 * Bump electron-builder
 * Add the icon url for the control panel entry

package.json

@@ -93,7 +93,7 @@
     "catw": "^1.0.1",
     "cpx": "^1.3.2",
     "css-raw-loader": "^0.1.1",
-    "electron-builder": "^7.10.2",
+    "electron-builder": "^7.23.2",
     "emojione": "^2.2.3",
     "expect": "^1.16.0",
     "fs-extra": "^0.30.0",
@@ -132,9 +132,13 @@
     "files": [
       "!**/*",
       "electron/src/**",
+      "electron/img/**",
       "vector/**",
       "package.json"
-    ]
+    ],
+    "squirrelWindows": {
+      "iconUrl": "https://riot.im/favicon.ico"
+    }
   },
   "directories": {
     "buildResources": "electron/build",