Non-square images should be scaled, not cropped

[igal]

The person that created the http://epdx.org/groups/pdx-se group uploaded a wide image, but Citizenry cropped it to the height of the image, which resulted in all but two letters of the logo being cropped out. He uploaded it multiple times, clearly frustrated and confused by it being cropped.

I worked around this by uploading a square version of the image, which is why it looks okay now -- I simply imported the image into Gimp and expanded the canvas height to match its width, and uploaded the result.

I recommend that we scale non-square images down so they're shown in their entirety, rather than cropping them. I suspect this is a very simple edit to the code handling the images.