* Exclude comments from brace parsing in vertex/fragment blocks
If a comment contained an opening brace { but not the matching
closing one, matc would not count braces properly and not find
the proper end of a vertex/fragment block.
* Add test
* Add clear coat normal map support
This change allows to set a separate normal map for the clear coat layer of a material.
* Document the new clearCoatNormal property
* Fix typo
