[HDP][Doc] Documentation about HDP plugin

[Alexander Ignatov]

Current Savanna documentation on readthedocs doesn't contain any content about HDP Plugin. Especially if it is targeted for 0.2.1. It would be great to have new pages about HDP:
- Page(s) should contain plugin overview, features, HDP version, supported services, etc.
- Cluster creation flow with convert() method;
- Simple rest examples;
- Image requirements;
- OpenStack Env preparing to work with plugin
- All other needed info

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/44928

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/44928
Committed: http://github.com/stackforge/savanna/commit/b449390c167e4ccddc1aa3dc2ff6cec8c64924db
Submitter: Jenkins
Branch: master

commit b449390c167e4ccddc1aa3dc2ff6cec8c64924db
Author: Erik Bergenholtz <email address hidden>
Date: Tue Sep 3 13:28:53 2013 -0400

    Documentation about HDP plugin

    Merging initial documentation changes for HDP plugin

    Change-Id: Ie29c2aad292198a0e90ffdfce2d63eba153f793d
    Fixes: bug #1204178

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/0.2
Review: https://review.openstack.org/45583

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/45583
Committed: http://github.com/stackforge/savanna/commit/716ac46c5815ca77023ad07b26d6765a3a9afaff
Submitter: Jenkins
Branch: stable/0.2

commit 716ac46c5815ca77023ad07b26d6765a3a9afaff
Author: Erik Bergenholtz <email address hidden>
Date: Tue Sep 3 13:28:53 2013 -0400

    Documentation about HDP plugin

    Merging initial documentation changes for HDP plugin

    Change-Id: Ie29c2aad292198a0e90ffdfce2d63eba153f793d
    Fixes: bug #1204178
    (cherry picked from commit b449390c167e4ccddc1aa3dc2ff6cec8c64924db)