Fix all failures in the lib-python winreg tests on both win32 and win64:
- Revert changes that broke
test_changing_value
- Implement the
...ReflectionKey
andDeleteKeyEx
functions for win64 hosts (both win32 and win64 running on win64) - Add
REG_QWORD
andREG_QWORD_LITTLE_ENDIAN
, added in CPython 3.6 - bpo-21151, REG_BINARY should round-trip
None
, CPython 2.7/3.4 - bpo-25778, truncate REG_SZ at the first NULL character, since CPython 3.6.1
- bpo-32587, make REG_MULTI_SZ support zero-length strings, since CPython 3.7