Chrome extension: region capture, and scrolling page capture

[manurana]

Great work!!
Just some thoughts for useful enhancements

Ability to capture a region
Ability to capture the full scrolling page

[daveearley]

Thanks for the suggestions! When I get some time I hope to add these features.

[steven2358]

+1 for the ability to capture a region

[daveearley]

For region capture, I've partially addressed that in the last PR I merged. I've added a crop feature