PBR_DEMO: Add the scene file to the project for easy editing access
PBR_DEMO/COMMON: Fix more size_t warnings with static_cast
PBR_DEMO: Rename the material to "simple"

Since it doesn't just apply to pine wood
DOCUMENATION: Update scene schema to reflect new material system
DOCUMENTATION: Minor file name pattern fix

Since output files are compiled, aka, not hlsl
PBR_DEMO: Create the simple scene
COMMON: Guarantee the subdivisions are valid
HMF_CONVERTER: Move ParseSamplerTypeFromString to Common

So other projects can use it
PBR_DEMO: Use the 64 bit version of AntTweakBar when we build 64 bit
DOCUMENTATION: Use lowercase enums

Easier to type
PBR_DEMO: Add crude support for all model types in a scene

I don't really like the idea of casting back and forth to a void pointer. Seems really
hacky. But I wanted to test to make sure all the scene logic was working.
Polymorphism seems like a possibility. Perhaps an abstract function to return a
new Model* in which each child implements?
PBR_DEMO: Add the referenced textures
PBR_DEMO: Radius is a Single

Doesn't really matter to the parser, but it may help the user if they don't
look at the schema
PBR_DEMO: Use the simple material shader

Since pine.hmat was renamed to simple.hmat
PBR_DEMO: Explicitly state the plane subdivisions and texture tiling

Since the current parsing code doesn't support default values yet.