A few tweaks for readme

* Reword the intro sentence to make CLI sound equally important as
  Python client :)

* Change clone url from tuskar org to stackforge org and change it to
  https, because ssh cloning requires the user to have a Github
  account.

* Format paragraphs to keep line length under 72 chars.

Change-Id: I07ab9a89076153691b75ba40aa569c59284e84dc
Merge "A few tweaks for readme"