Add OpenGL fallback DLLs to Windows Python wheels

d3dcompiler_XX.dll and opengl32sw.dll are not included in the Windows Python wheels.

Due to dynamic OpengGL leading[0] if OpenGL >=2.0 is not available Qt will try ANGLE[1].

ANGLE requires three DLL files

• libEGL.dll (included)
• libGLESv2.dll (included)
• d3dcompiler_XX.dll (not included)

d3dcompiler_XX.dll is the DirectX shader compiler[2], "where XX is the version number that ANGLE (libGLESv2) was linked against." [1]

If OpenGL >= 2.0 is not available and ANGLE is not available Qt will fallback to a software renderer.

This requires opengl32sw.dll [1] which is not included in the wheel.

0: https://blog.qt.io/blog/2014/11/27/qt-weekly-21-dynamic-opengl-implementation-loading-in-qt-5-4/

1: http://doc.qt.io/qt-5/windows-deployment.html#creating-the-application-package

2: https://github.com/Microsoft/DirectXShaderCompiler