Remove a '__main__' handler from __init__.py.

sql lexer: Add temporal support keywords

Fix #1247 by looking up in both HKLM and HKCU.

* Fix an issue raised in the review -- don't raise None no matter what.
* Remove a few variables to make the control flow easier to understand

Add Windows CI support & fix tests on Windows

This is slightly different from the code posted inside the issue:
* Use finally to close the registry key no matter what
* Don't use break, but return directly on the first hit

This fixes three test failures on Windows:
* Two due to incorrect handling of : (on Windows, multiple : can
  be part of a path.)
* One due to newline differences