[Backport 1.9] COMPASS 1743 🐛 Open all links with the system browser (#1224) (#1225)

* COMPASS 1743 🐛 Open all links with the system browser

Includes intercom links.
Also means we can drop the shell.openExternal overrides, used in many <InfoSprinkle> cases, at a later date.

* 🎨 e -> event

https://github.com/ryanmcdermott/clean-code-javascript#avoid-mental-mapping

It's also recommended in:
https://github.com/electron/electron/blob/master/docs/api/web-contents.md#event-new-window

Author: pzrq

src/main/window-manager.js

@@ -181,6 +181,14 @@ var createWindow = module.exports.create = function(opts) {
       detach: true
     });
   }
+
+  /**
+   * Open all external links in the system's web browser.
+   */
+  _window.webContents.on('new-window', function(event, url) {
+    event.preventDefault();
+    electron.shell.openExternal(url);
+  });
   return _window;
 };