added windows shader
add halftone shader
add halftone shader option to demo
add support for booleans in JS->GLSL uniform translation
use boolean uniform for halftone color switcher
added windows shader
Merge branch 'windows' of github.com:tangram-map/tangram into windows

Conflicts:
	demos/gl_styles.yaml
	index.html
Merge branch 'master' into windows

Conflicts:
	demos/gl_styles.yaml
cleanup
removed unused uniforms
Merge pull request #9 from tangram-map/windows

Adding Windows shader
Merge branch 'master' into color-halftone

Conflicts:
	demos/gl_styles.yaml
	index.html
cleanup
cleanup
added color halftone