Windows: Enable kill (part one)

Signed-off-by: John Howard <jhoward@microsoft.com>

signal/signal_unsupported.go

@@ -1,4 +1,4 @@
-// +build !linux,!darwin,!freebsd
+// +build !linux,!darwin,!freebsd,!windows
 
 package signal
 

signal/signal_windows.go

@@ -14,3 +14,14 @@ const (
 	// DefaultStopSignal is the syscall signal used to stop a container in windows systems.
 	DefaultStopSignal = "15"
 )
+
+// SignalMap is a map of "supported" signals. As per the comment in GOLang's
+// ztypes_windows.go: "More invented values for signals". Windows doesn't
+// really support signals in any way, shape or form that Unix does.
+//
+// We have these so that docker kill can be used to gracefully (TERM) and
+// forcibly (KILL) terminate a container on Windows.
+var SignalMap = map[string]syscall.Signal{
+	"KILL": syscall.SIGKILL,
+	"TERM": syscall.SIGTERM,
+}