Html5 js host support

Latest HTML5 JS host.

Rebased to latest development. I'm not sure how your cmake was working with the current setup but using a copy of your blackberry build script the paths in the third party libs were traversing back one level too far. I tried to keep those mods in a different commit so that you could skip it easily. 

Just watch out for the freetype cmake file, that has been rewritten so as not to build/export things twice (h files include c files!). 

A little bit lazy with my GL Enum remapping, just defined BUILD_NACL to pick up the enum mappings.

I have excluded glew from third-party for html build but It was done differently to how you did it for blackberry. Feel free to change it.

I stub out all of untz sources with a webversion for the untz lib. This is done with a big `IF` block in the cmake file for untz. Maybe it would be better to be a different cmake file.

The readme's will need to be updated, I'll do that later.