Make get/put more robust

- init folder if not present already in 'get()' call
  - put.go was referencing wrong args - fix it
  - if no OBJECTNAME is specified during 'get' - grab a
    list of files under "~/.minio"
  - Provide new API GetList() for ObjectStorage struct

cmd/erasure-demo/put.go

@@ -1 +1,33 @@
 package main
+
+import (
+	"log"
+	"os"
+
+	"github.com/codegangsta/cli"
+)
+
+func put(c *cli.Context) {
+	config, err := parseInput(c)
+	if err != nil {
+		log.Fatal(err)
+	}
+	filePath := c.Args().Get(0)
+	if len(filePath) == 0 {
+		log.Fatal("Please specify a valid object name \n # erasure-demo put <OBJECTNAME>")
+	}
+	inputFile, err := os.Open(filePath)
+	if err != nil {
+		log.Fatal(err)
+	}
+	switch config.storageDriver {
+	case "fs":
+		{
+			fsPut(config, c.Args().Get(0), inputFile)
+		}
+	default:
+		{
+			log.Fatal("Unknown driver")
+		}
+	}
+}