Image Viewer Changes

So I have added a feature so that large vertical images are displayed on screen rather than only the top of them (since they were previously filled horizontally). It detects the size of the image and then resizes onto the screen, there is a slight offset that I should probably fix too.

The second change is the addition of shortcuts, left and right arrow to switch from one image to the next, and also the Esc key to close the image viewer.

I was also thinking that there should be a hotkey to open the image viewer, but I haven't got any good ones. Thoughts?