There are a number of documentation pages, eg
http://orgmode.org/worg/org-tutorials/org4beginners.html
http://orgmode.org/worg/org-faq.html

that recommend to use

(require 'org-install)

However org-install itself says:

;; The file org-install is obsolete.
;;
;; It is provided here so that (require 'org-install) does not
;; trigger an error for users with obsolete Emacs configuration.
;; You can safely remove (require 'org-install) from your config."

And contains nothing else!!

So what exactly is the case?

What is the setup procedure recommended for git-installed org?