Added SetupDiOpenDevRegKey(..), SetupDiEnumDeviceInfo(..) and some constants

I added the following items to the Win32 SetupApi
* SetupDiOpenDevRegKey(..) 
* SetupDiEnumDeviceInfo(..) 
* some constants associated with SetupDiOpenDevRegKey(..)
* Tests both methods

The JavaDocs are copied from MSDN, is this a legal problem?

You didn't write the whole thing, right? You should remove this or fish all the names from git history and add them too.