Shader family format

[Josh]

In the next build, the shader family structure will be simplified. The engine will continue to be backwards compatible with the old structure. Basically, I got rid of the float precision and static/dynamic branches, and put all the shaders in a "shaders" node.

No changes are needed to your existing shader family files.

{
	"shaderfamily":
	{
		"textures":
		[
			"Base"
		],
		"shaders":
		{
			"mask":
			{
				"default":
				{
					"base":
					{
						"vertex": "Shaders/2D/2D.vert",
						"fragment": "Shaders/2D/2D.frag",
						"transparency": "Shaders/2D/2D_Masked.frag"
					}
				}				
			},
			"opaque":
			{
				"default":
				{
					"base":
					{
						"vertex": "Shaders/2D/2D.vert",
						"fragment": "Shaders/2D/2D.frag",
						"transparency": "Shaders/2D/2D_Masked.frag"
					}
				}
			}
		}			
	}
}