Windows: cleanup preprocessor definition namespace

Windows: cleanup preprocessor definition namespace

Do not use reserved preprocessor symbol names.  Instead
use OPENAFS_<PATH>_<HEADER>_H formatted names where <PATH>
is the subdirectory path from src/ in which the header
file originates in the repository.

Change-Id: I998d7feeddeb9660f3fc514e2ba752c54e402a24
Reviewed-on: http://gerrit.openafs.org/3599
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>