Replace internal map usage with slices

[kettek]

I'm currently optimizing a particle effects subsystem and am running into some performance issues with a large amount of particles (1000+). Although I'm not expecting there to be that many particles with physics enabled, I fully expect there to be an impact from them during complex scenes (I was already seeing this, but optimized my own code as well to make it a bit better). My primary game map developer has a penchant for using lots of available systems to make things look really nice, but this comes at the cost of my own time spent optimizing.

At any rate, after some profiling, removing the usage of maps in a few locations (the ignore list and within the Object.Check func) gives a decent increase in performance -- was able to reduce Check's processing time by around 5 seconds (from 7.5 to 2.5, roughly). Clipped profiling is provided below.