Revendor github.com/Microsoft/hcsshim

1. Revendors github.com/Microsoft/hcsshim to the latest known good commit.
This includes numerous bug fixes and improvements.

2. Vendors indirect dependency on go.opencensus.io since hcsshim now uses trace
correlation.

Signed-off-by: Justin Terry (VM) <juterry@microsoft.com>

vendor/github.com/Microsoft/hcsshim/internal/log/g.go

@@ -0,0 +1,23 @@
+package log
+
+import (
+	"context"
+
+	"github.com/sirupsen/logrus"
+	"go.opencensus.io/trace"
+)
+
+// G returns a `logrus.Entry` with the `TraceID, SpanID` from `ctx` if `ctx`
+// contains an OpenCensus `trace.Span`.
+func G(ctx context.Context) *logrus.Entry {
+	span := trace.FromContext(ctx)
+	if span != nil {
+		sctx := span.SpanContext()
+		return logrus.WithFields(logrus.Fields{
+			"traceID": sctx.TraceID.String(),
+			"spanID":  sctx.SpanID.String(),
+			// "parentSpanID": TODO: JTERRY75 - Try to convince OC to export this?
+		})
+	}
+	return logrus.NewEntry(logrus.StandardLogger())
+}