[PATCH] escape key and clicking on background close display

[snarfed]

hi! one of the (few!) things that originally confused me about shutter was how to close it. i didn't immediately think to click on the image in the display.

this patch makes the escape key and clicking on the background div also close the display.

one catch: clicking on the background left and right of the image doesn't close shutter, which isn't great for consistency. the problem is that those sides are covered by div#shWrap, which also covers the prev/next navigation links below the image, so clicking prev/next would end up closing shutter. I tried stopping the event from bubbling/propagation, increasing #shTitle's z-index to put it on top of #shWrap, etc, but no luck. grr. ah well.