In the DirectShow plugin the conversion from MEDIASUBTYPE_RGB32 is wrong (RGB <-> BGR)

The MEDIASUBTYPE_RGB32 byte order is BGRA:
http://msdn.microsoft.com/en-us/library/windows/desktop/dd407253(v=vs.85).aspx

On Windows, the byte order of QImage::Format_RGB32 is also BGRA (little-endian), so no need for rgb swap, but currently the DirectShow plugin does that.