d3dx9_36: Start effect parsing.

[Henri Verbeet]

2011/3/13 Rico Schüller <kgbricola at web.de>:
> +    if (tag != 0xfeff0901)
Looks like the kind of thing you'd want a constant or inline function
for. If I were to guess, the feff part means it's an effect (similar
to the ffff for d3d9 pixel shaders and the fffe for d3d9 vertex
shaders), and 0901 for version 9.1 (also similar to the d3d9 shader
version token).