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?

I think just the opposite, its noise if the same code is duplicated in several places, it distracts the reader form the essicial, just a matter of taste...