[engine][directx]Fixes #120: Wrong u,v coordinates were given, because of int/int division rounding.
u,v coordinates need be calculated in floating point division.
[win]Fixes #125 and #117 by adjusting pixel to texel ratio on DirectX9.

See this for clarification:
http://msdn.microsoft.com/en-us/library/windows/desktop/bb219690(v=vs.85).aspx