Make toolbar complain on disabled choices
Guard against browser being None when grabbing a screenshot

Wasn't sure why we were asking for a PNG and then converting to base64
when selenium knows how to give us the base64. Comments?
Merge pull request #854 from seandst/browser-none-screenshot

Guard against browser being None when grabbing a screenshot
Merge pull request #849 from mfalesni/complain

Make toolbar complain on disabled choices