directory structure change to work with glide

glide has its own requirements. My previous workaround caused me some
code checkin errors. Need to fix this.

weed/command/version.go

@@ -0,0 +1,24 @@
+package command
+
+import (
+	"fmt"
+	"runtime"
+
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+var cmdVersion = &Command{
+	Run:       runVersion,
+	UsageLine: "version",
+	Short:     "print SeaweedFS version",
+	Long:      `Version prints the SeaweedFS version`,
+}
+
+func runVersion(cmd *Command, args []string) bool {
+	if len(args) != 0 {
+		cmd.Usage()
+	}
+
+	fmt.Printf("version %s %s %s\n", util.VERSION, runtime.GOOS, runtime.GOARCH)
+	return true
+}