Popup icon on high-DPI screens

[nuclearpidgeon]

The toolbar/popup icon has been confirmed as not showing up on Chrome on Windows 8 on a Microsoft Surface (thanks @crozone !). I believe the issue is that the supplied icon doesn't conform to the two new image sizes required in the mainfest file: https://developer.chrome.com/extensions/browserAction#manifest .

This should be an easy fix, I will upload new exports of the logo at the appropriate sizes.