The minecraft's original Raytraces works poorly. It provides no method for filtering blocks, and it doesn't support combining blocks and entities together for tracing. We should customize a Raytrace to handle our complex needs.

Currently there are a few notes:

• Combine tracing of entities and blocks
• Entity filters and Block filters to ignore a specific kind(s) of blocks
• Ability to dynamically&conveniently alter those tracing options at runtime.

Minecraft has it's own rayTrace alg, but I didn't go over them completely. Should we write a new alg or reuse the MC code carefully? (I prefer the first one)

Fixed in LIUtils.