Fix CHEF-4419 by appending a drive letter from the current working directory to the path if it starts with '/' in the most common code path we're encountering this issue.
Fix the annoying warning when running specs on windows.
Fix comment about CHEF-4427.
Merge pull request #1018 from opscode/OC-10077

OC-10077: Port CHEF-4419 fix to be included in 11.8.