Combine all sprites into a sprite sheet

[dealproc]

Looking at the repo as it exists now, there are many little 1k *.png images that represent each of the emoticons that are usable within JabbR. It would be a nice-to-have if these emoticons were in a sprite sheet, then used onscreen using a span; em; or similar tag to show the image on the sheet. This would reduce # of requests from the server just to show images.