Replace Image for Visual Syms

In sym creation, the sym creator will see an option to Replace Screen when adding Hot Spots, Script Lines and sequencing the interactions. This allows the sym creator to replace that screen or screens that might have slight cosmetic changes to them that would not interfere with the hot spots on the screen. If the screen view changes the Hot Spots, the sym creator will want to delete the screen and add a new one, then readd the Hot Spots.