Imports of package overlayfs

PathSynopsis
github.com/spf13/afero
ioPackage io provides basic interfaces to I/O primitives.
io/fsPackage fs defines basic interfaces to a file system.
osPackage os provides a platform-independent interface to operating system functionality.
syncPackage sync provides basic synchronization primitives such as mutual exclusion locks.
timePackage time provides functionality for measuring and displaying time.