Import of code from heimdal

Import of code from heimdal

This commit updates the code imported from heimdal to
b8a53329fc8bf2fe8c4f4058512f828d7654e3f8 (switch-from-svn-to-git-3003-gb8a5332)

Upstream changes are:

Jeffrey Altman (2):
      Windows: rk_strdup allocator
      Windows: rk_wcsdup allocator

Nicolas Williams (1):
      Fix bug in _krb5_expand_path_tokensv()

Change-Id: I08abb25b4f4136bccb3eaf8d8c44851ce748f395
Reviewed-on: http://gerrit.openafs.org/7842
Reviewed-by: Derrick Brashear <shadow@dementix.org>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>