Fix https://github.com/opscode/chef/issues/1842 by calling PathHelper.canonical_path, so that (among other things) we don't add the prepender to relative paths.
Test for github issue 1842: handle relative paths correctly on Windows.
Don't change the working directory to something that probably gets deleted: Windows doesn't care, but the Unixen get very unhappy.
Stop using homegrown canonicalize() and use Chef::Util::PathHelper.paths_eql?.
Remove unnecessary variable.
Random wrong canonicalize() -> PathHelper.paths_eql?().
Merge pull request #1901 from opscode/dont-prepend-to-relative-paths

Don't prepend \\?\ to relative paths, it produces an invalid path argument. Fixes issue #1842.