This allows to load them with LOAD_LIBRARY_AS_DATAFILE.

When mode is STGM_WRITE or STGM_READWRITE make sure key key exists.
Only read data in STGM_READ or STGM_READWRITE mode.
Do not depend on value type being REG_BINARY.
Succeed when reading not existing values.

Add comments to functions that are not implemented.

On Write holes between file size and cursor are filled with 0 bytes.
On SetSize holes caused by increasing file size are filled with 0 bytes.

Releasing the device earlier may cause the underlying wineD3D device
to be freed before the child object has had a chance to clean up.

The Mac Nvidia driver doesn't implement the result.clip part of
GL_NV_vertex_program2_option correctly. It complains about a syntax
error if "result.clip[0]" is used. "result.clip" compiles correctly, but
supports only one clipplane, and running the shader results in severe
rendering bugs.