* Examples: use .texture of input render targets.

* Assign null instead of undefined.

remove material.ambient from everything per discussion here: https://github.com/mrdoob/three.js/pull/5741#issuecomment-67893202

Also change use of setClearColorHex to setClearColor.

Cleaned up custom stats.js styling in examples (thanks to @mrdoob for showing me this is possible ;).

Renamed screen shader to blit.
Throwing errors in *Pass if the shader aren't available.

All examples should work now.

The only weird thing seems to be that for some reason bone texture doesn't like to be assigned to arbitrary texture unit (or more precisely to alternating texture units).

See #2340

Sorry that you had to add it @alteredq.

Still needs to be done: canvas renderer / picking / canvas examples.

I think normal map scale needs to be now positive, though not sure, it just looks closer to how it was before with positive scale, also mole on the right cheek is elevated instead of sunk.

This should be the last one. The only ones left should be "webgl_postprocessing" and "webgl_postprocessing_dof" where I got stuck.

Except special cases like 3d renderers and cube cameras all examples should be now without warnings.