Windows: Do not install IBM AFS HLP files

Windows: Do not install IBM AFS HLP files

The IBM AFS HLP files are so out of date at this point
that they are simply confusing.  They reference tools and screens
that no longer exist and claim the product is "IBM AFS".  Incorrect
documentation is worse than no documentation.

The HLP files cannot be updated since we do not have the sources.

HLP file format is no longer supported on Windows Vista or 7.

The afs-nt.hlp file will continue to be installed conditionally
when afscreds.exe is installed but the shortcut to it in the
Start menu is being removed.  afscreds.exe is not installed by
default.

Change-Id: I3443a5c4ca65472a16cbf7ae1d52da39e917136a
Reviewed-on: http://gerrit.openafs.org/6065
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>