Fix for geometry.maxInstancedCount == 0

WebGLRenderer: loadUniformsGeneric() back to if statements. Chrome seems to be continuously deoptimizing the function. Maybe helps with #8220.

add ability to have texel encodings (RGBE,RGBM,etc.) on envMap and emissiveMap that can contain unbounded intensities.

Refactored shadowmap code again. Android/Adreno doesn't fails to support bool and mat4 in structs...

Currently MeshBasicMaterial/MeshLambertMaterial doesn't support shadows. Not sure if they'll get that back.

This reverts commit 644d6a21.

Conflicts:
	src/materials/Material.js

This commit enables three.js to manage the stencil buffer via material
properties.