add "cluster ls", put "status" into "cluster status" (#5)

pkg/cfg/config.go

@@ -30,7 +30,7 @@ import (
 )
 
 const (
-	Version string = `v0.0.2`
+	Version string = `v0.0.3`
 )
 
 type Cluster struct {
@@ -49,6 +49,7 @@ type Config struct {
 	From, To, MaxItems int      // search: flags
 	Filter             []string // search: -F
 	Exclude            string   // cluster compare: -e (regexp)
+	All                bool     // cluster status: -a
 }
 
 func NewConfig() *Config {