Workaround missing escape_glob in chef-dk 0.3.5

We don't have Chef::Util::PathHelper.escape_glob in chef-dk 0.3.5, but will
in the next release. Work around that. Also, clarify what trusted_certs contains
and fix it to work on Windows systems without mingw.

Fixes #148
vendored in cleanpath as well
Merge remote-tracking branch 'upstream/master' into smurawski/testwsman