Modify the API in Advapi32Util for support registryGetKey() in WOW64 flag

For Advapi32Util support the WOW64 flag 
reuse the current API registryGetKey() to open the WOW64 flag

Ex:
HKEYByReference phkKey = registryGetKey(WinReg.HKEY_CURRENT_USER, "Software\\JNA", WinNT.KEY_READ | WinNT.KEY_WOW64_32KEY);
String value = registryGetKeys(phkKey.getValue(), 'StringKey');
registryCloseKey(phkKey.getValue());

On UnitTest, 
I think original testcase would include the new API testing

BTW, I think this may fit the feature request #101