Fallout3 Shader Properties update

Updated BSShaderProperty, BSShaderLightingProperty, BSShaderNoLightingProperty, BSShaderPPLightingProperty and SkyShaderProperty blocks for Fallout3. Added BSShaderFlags2 and their meanings.
Reverted names of Unknowns

Reverted names of two Unknowns in BSShaderPPLightingProperty to "Unknown Float 4" and "Unknown Float 5". Also renamed "Envmap Scale" in BSShaderProperty to "Environment Map Scale" and added its description of funtionality - it is same as "Environment Map Scale" in BSLightingShaderProperty - controls the intesity of the environment map.
Merge pull request #29 from ttl269/feature/Shader-Properties-update

Fallout3 Shader Properties update