This commit introduces a SSS-oriented intersection structure which is replacing old logic of having separate arrays for just intersections and shader data and encapsulates all the data needed for SSS evaluation. This giver a huge stack memory saving on GPU. In own experiments it gave 25% memory usage reduction on GTX560Ti (722MB vs. 946MB). Unfortunately, this gave some performance loss of 20% which only happens on GPU. This is perhaps due to different memory access pattern. Will be solved in the future, hopefully. Famous saying: won in memory - lost in time (which is also valid in other way around).