Environment map, vertex texture++, ozGenEnvMap

- ozEngine
  * GL::textureDataFromFile() supports non-GL_TEXTURE_2D textures
- client
  * animated mesh positions and normals joined in one vertex texture
    => performance++
  * texture LOD config option
  * environment map in (glsl/env??.dds) => performance--
  * shader.envMap setting, render.lowDetail -> shader.lowDetail
  * AL_REFERENCE_DISTANCE replaced by AL_ROLLOFF_FACTOR
- tools
  * ozGenEnvMap generates environmet (noise) cube map