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?

as the javadoc states the test can have two different outcomes that are valid, but it depends on your hardware, not all machines have serial-port, so what to do here?