Imports of package wcow

PathSynopsis
github.com/Microsoft/hcsshim/internal/copyfile
github.com/Microsoft/hcsshim/internal/wclayerPackage wclayer provides bindings to HCS's legacy layer management API and provides a higher level interface around these calls for container layer management.
github.com/sirupsen/logrusPackage logrus is a structured logger for Go, completely API compatible with the standard library logger.
osPackage os provides a platform-independent interface to operating system functionality.
path/filepathPackage filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths.