Windows: PopulateCurrentEntry Symlink Targets

Handle a broader range of symlink target formats and be more
precise regarding what is an afs symlink or a dfs link.

Change-Id: Ia37c1adf5d64ba44fffca976885a455e6900a047
Reviewed-on: http://gerrit.openafs.org/9428
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>