Implementation of D3DXGetFVFVertexSize with tests

[David Adam]

Hello,

to keep the code readable, you should put your function in a new file. For
instance,
d3dx8/mesh.c would be fine  (msdn put this functio in the mesh category).
Otherwise, the whole code is going to implemented in the file
d3dx8/d3dx8_main.c.

What is the purpose of the line

+    ok(TRUE,"prueba");
?

Moreover, I think that this test should be implemented in d3dx8 too. If you
want to test the difference between d3d8 and d3dx9, you should duplicate the
test in d3dx9 then.

David