ShaderGenerator: normalize tangent/binormal/normal after interpolation
ShaderGenerator: normalize tangent/binormal/normal after interpolation

Also changes l_eye_normal interpolant from float4 to float3.

chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d,chandler14362/panda3d