Update README, fix formatting in tutorial

* README.rst: Add ceilometer and swift services config.

contrib/devstack/
* README.rst: Remove file, to avoid duplication of contents in
  congress/README.rst.

doc/source/
* tutorial-tenant-sharing.rst: Update URL to devstack steps. Fix lines past 79
  characters. Fix preformatted blocks.

Change-Id: Icd2c78d805fa6baadac74c7cb73b5478024a38bc
Merge "Update README, fix formatting in tutorial"