Metallic-Roughness shading model Graphic3d_TOSM_PBR has been implemented.
New materials descriptors Graphic3d_PBRMaterial have been added to Graphic3d_MaterialAspect.
PBR shading model requires OpenGL 3.0+ or OpenGL ES 3.0+ hardware.
Environment cubemap is expected to be provided for realistic look of metallic materials.
occLight_IsHeadlight() now returns bool instead of int.
Avoid using lowp for enumerations to workaround occLight_IsHeadlight()
ignorance on Adreno 308 caused by some GLSL optimizator bugs.
OpenGl_Texture::EstimatedDataSize() - fixed estimation for Cubemap textures.
OpenGl_Sampler::applySamplerParams() - fixed uninitialized GL_TEXTURE_WRAP_R in case of GL_TEXTURE_CUBE_MAP target.
