Add domain and subdomain support for MinioAPI

This change brings in domain and subdomain support

   - ./minio --domain "yourminiodomain.com"

This change brings in a much needed feature by keeping
bucketnames as part of your 'DNS' name.

All your existing applications can be migrated off from s3 to
Minio without little to no modifications.

NOTE: Setting up DNS for your `buckets` is out of scope of this feature

pkg/api/minioapi/object_handlers.go

@@ -103,6 +103,12 @@ func (server *minioApi) putObjectHandler(w http.ResponseWriter, req *http.Reques
 	bucket = vars["bucket"]
 	object = vars["object"]
 
+	resources := getBucketResources(req.URL.Query())
+	if resources.policy == true && object == "" {
+		server.putBucketPolicyHandler(w, req)
+		return
+	}
+
 	err := server.storage.StoreObject(bucket, object, "", req.Body)
 	switch err := err.(type) {
 	case nil: