Imports of shimdiag command

PathSynopsis
contextPackage context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes.
errorsPackage errors implements functions to manipulate errors.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
github.com/Microsoft/hcsshim/internal/appargsPackage appargs provides argument validation routines for use with github.com/urfave/cli.
github.com/Microsoft/hcsshim/internal/cmdPackage cmd provides functionality used to execute commands inside of containers or UVMs, and to connect an upstream client to those commands for handling in/out/err IO.
github.com/Microsoft/hcsshim/internal/shimdiagCode generated by protoc-gen-go-ttrpc.
github.com/containerd/console
github.com/urfave/cliPackage cli provides a minimal framework for creating and organizing command line Go applications.
ioPackage io provides basic interfaces to I/O primitives.
osPackage os provides a platform-independent interface to operating system functionality.
os/signalPackage signal implements access to incoming signals.
syscallPackage syscall contains an interface to the low-level operating system primitives.
text/tabwriterPackage tabwriter implements a write filter (tabwriter.Writer) that translates tabbed columns in input into properly aligned text.