restoring the `cached_file` helper as downstream cookbooks use it.
restoring the `cached_file` helper as downstream cookbooks use it.

Signed-off-by: Steven Murawski <8669c3d8a26fdfd690b7fe59e147997ca1cfb23f@gmail.com>

stuartpreston/windows,opscode-cookbooks/windows,chef-cookbooks/windows,GannettDigital/chef-windows,criteo-forks/windows,rlaveycal/windows,protec-cookbooks/windows,daptiv/windows,ruicovelo/windows