[ESME-284] More cleanup - these images are not necessary with the static view, and would need to be recreated (ESME-296) anyway if we want to use a dynamically resizing approach.
incubator/esme/trunk/server/src/main/webapp/images/bg-update-bot.png
incubator/esme/trunk/server/src/main/webapp/images/bg-update-mid.png
incubator/esme/trunk/server/src/main/webapp/images/bg-update-top.png
