New check icons in administrative interface

Previously, when someone redeemed a prize, s/he would see either a red x or a green check to indicate redeemed or not redeemed. This is also the look for marking off learning track activities and completing or enrolling someone in a program. Some staff members found this confusing, and as such, we have changed to having the not-redeemed or incomplete state for something be represented by an empty box. When you click on the box and see a checkmark, that item is now complete. 

Initially requested by Fort Vancouver Regional Library