Re: d3dx9: CloneMesh test and improvements

[Michael Mc Donnell]

I've changed the implementation, like suggested by Matteo and Stefan,
to first convert to FLOAT4 and then to the respective types. I've
implemented conversion from FLOAT1-4 to the other types, except for
UDEC3 and DEC3N.

I've also changed the tests quite a bit to catch a lot of edge cases
with rounding, overflow and clamping. I ended up using a  simple
rounding method which gives the correct behavior:

+static INT simple_round(FLOAT value)
+{
+    int res = (INT)(value + 0.5f);
+
+    return res;
+}

I'll continue to add more tests for the other types and implement the
remaining conversions.