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
~~~

flags.go

@@ -1,5 +1,5 @@
 /*
- * Minio Cloud Storage, (C) 2015 Minio, Inc.
+ * Minio Cloud Storage, (C) 2015, 2016 Minio, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,28 +27,6 @@ var (
 		Value: mustGetConfigPath(),
 		Usage: "Path to configuration folder.",
 	}
-
-	addressFlag = cli.StringFlag{
-		Name:  "address",
-		Value: ":9000",
-		Usage: "ADDRESS:PORT for cloud storage access.",
-	}
-
-	accessLogFlag = cli.BoolFlag{
-		Name:  "enable-accesslog",
-		Hide:  true,
-		Usage: "Enable access logs for all incoming HTTP request.",
-	}
-
-	certFlag = cli.StringFlag{
-		Name:  "cert",
-		Usage: "Provide your domain certificate.",
-	}
-
-	keyFlag = cli.StringFlag{
-		Name:  "key",
-		Usage: "Provide your domain private key.",
-	}
 )
 
 // registerFlag registers a cli flag