This fixes errors in ownership on directory creation during build that
can cause inaccessible files depending on the paths in the Dockerfile
and non-existing directories in the starting image.
Add tests for the mkdir variants in pkg/idtools
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Upstream-commit: ae8c004dc18c59fec9cd67759a5e0087300e872d
Component: engine
