Enable and disable writing of frame buffer color components

Property definitions

glesv2 :: glesv2 $ Sys :: glColorMask
# Enable and disable writing of frame buffer color components
fun glColorMask(red, green, blue, alpha: Bool) `{ glColorMask(red, green, blue, alpha); `}
lib/glesv2/glesv2.nit:852,1--853,90