Revise swarm init/update flags, add unlocking capability

- Neither swarm init or swarm update should take an unlock key
- Add an autolock flag to turn on autolock
- Make the necessary docker api changes
- Add SwarmGetUnlockKey API call and use it when turning on autolock
- Add swarm unlock-key subcommand

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>

api/server/middleware/debug.go

@@ -64,7 +64,7 @@ func maskSecretKeys(inp interface{}) {
 	if form, ok := inp.(map[string]interface{}); ok {
 	loop0:
 		for k, v := range form {
-			for _, m := range []string{"password", "secret", "jointoken", "lockkey"} {
+			for _, m := range []string{"password", "secret", "jointoken", "unlockkey"} {
 				if strings.EqualFold(m, k) {
 					form[k] = "*****"
 					continue loop0