Use github.com/pkg/xattr for extended attributes

vendor/src/github.com/pkg/xattr/README.md

@@ -0,0 +1,21 @@
+xattr
+=====
+Extended attribute support for Go (linux + darwin + freebsd).
+
+"Extended attributes are name:value pairs associated permanently with files and directories, similar to the environment strings associated with a process. An attribute may be defined or undefined. If it is defined, its value may be empty or non-empty." [See more...](https://en.wikipedia.org/wiki/Extended_file_attributes)
+
+
+### Example
+```
+  const path = "/tmp/myfile"
+  const prefix = "user."
+
+  if err = Setxattr(path, prefix+"test", []byte("test-attr-value")); err != nil {
+    t.Fatal(err)
+  }
+
+  var data []byte
+  data, err = Getxattr(path, prefix+"test"); err != nil {
+    t.Fatal(err)
+  }
+```