added delay before shader compilation is triggered, to reduce mid-edit compiles.
added delay before shader compilation is triggered, to reduce mid-edit compiles.

QingchaoHu/glsl-sandbox,CortesHub/glsl-sandbox,mrdoob/glsl-sandbox,beni55/glsl-sandbox,oresmus/glsl-sandbox,CortesHub/glsl-sandbox,mrdoob/glsl-sandbox,RobertoMalatesta/glsl-sandbox,mrdoob/glsl-sandbox,RobertoMalatesta/glsl-sandbox,oresmus/glsl-sandbox,oresmus/glsl-sandbox,mrdoob/glsl-sandbox,beni55/glsl-sandbox,RobertoMalatesta/glsl-sandbox,QingchaoHu/glsl-sandbox,CortesHub/glsl-sandbox,QingchaoHu/glsl-sandbox,beni55/glsl-sandbox