Implement #7347. Add CreateKeyEx, DeleteKeyEx, and update _winreg tests.

*ReflectionKey functions used to not be documented or tested, but they are
now sufficiently documented and tested on platforms where they apply.
Additionally, fixed a bug in QueryReflectionKey which was returning an
incorrect value.

All tests pass from XP through Windows 7, on 32 and 64-bit platforms.
3 files changed