Windows debug tweaks

This PR updates a few things for the Windows build, mostly dealing with debug info:

- Copy DLLs from Qt's lib dir, if any.  This is where DLLs from qt-mobility will be if they are installed into the Qt tree.

- Use the _d postfix where needed so a debug Python (python_d.exe) can import the debug PySide extensions.

- Trick distutils/setuptools into using the PyVer and platform architecture tags when building eggs, etc.  This is done by specifying an Extension object eventhough it is never actually build by distutils.  There may be a better way to do this.