config/main: Re-write config files - add to new config v3

- New config format.

```
{
	"version": "3",
	"address": ":9000",
    "backend": {
          "type": "fs",
          "disk": "/path"
    },
	"credential": {
		"accessKey": "WLGDGYAQYIGI833EV05A",
		"secretKey": "BYvgJM101sHngl2uzjXS/OBF/aMxAN06JrJ3qJlF"
	},
	"region": "us-east-1",
	"logger": {
		"file": {
			"enable": false,
			"fileName": "",
			"level": "error"
		},
		"syslog": {
			"enable": false,
			"address": "",
			"level": "debug"
		},
		"console": {
			"enable": true,
			"level": "fatal"
		}
	}
}
```

New command lines in lieu of supporting XL.

Minio initialize filesystem backend.
~~~
$ minio init fs <path>
~~~

Minio initialize XL backend.
~~~
$ minio init xl <url1>...<url16>
~~~

For 'fs' backend it starts the server.
~~~
$ minio server
~~~

For 'xl' backend it waits for servers to join.
~~~
$ minio server
... [PROGRESS BAR] of servers connecting
~~~

Now on other servers execute 'join' and they connect.
~~~
....
minio join <url1> -- from <url2> && minio server
minio join <url1> -- from <url3> && minio server
...
...
minio join <url1> -- from <url16> && minio server
~~~

globals.go

@@ -16,7 +16,26 @@
 
 package main
 
+import "github.com/fatih/color"
+
 // Global constants for Minio.
 const (
 	minGoVersion = ">= 1.6" // Minio requires at least Go v1.6
 )
+
+// minio configuration related constants.
+const (
+	globalMinioConfigVersion = "3"
+	globalMinioConfigDir     = ".minio"
+	globalMinioCertsDir      = ".minio/certs"
+	globalMinioCertFile      = "public.crt"
+	globalMinioKeyFile       = "private.key"
+	globalMinioConfigFile    = "config.json"
+)
+
+// global colors.
+var (
+	colorMagenta = color.New(color.FgMagenta, color.Bold).SprintfFunc()
+	colorWhite   = color.New(color.FgWhite, color.Bold).SprintfFunc()
+	colorGreen   = color.New(color.FgGreen, color.Bold).SprintfFunc()
+)