Switch OPENSHIFT_APP_UUID to equal the Mongo application '_id' field

* Add a migration to change OPENSHIFT_APP_UUID
* Ruby threaddump should tell the user to use the -g <gearid> option always
* Upgrade script should do the http check for gears with a git repo
* Rest API should return "app._id" always instead of "app.uuid"
* Pass "_id" to mcollective
* This results in a outage upgrade
Fix test cases
Merge remote-tracking branch 'origin/master' into propagate_app_id_to_gears

Conflicts:
	node/lib/openshift-origin-node/model/upgrade.rb
	node/test/unit/upgrade_test.rb
	plugins/msg-node/mcollective/src/openshift.rb
Merge remote-tracking branch 'origin/master' into propagate_app_id_to_gears
Merge remote-tracking branch 'origin/master' into propagate_app_id_to_gears

Conflicts:
	cartridges/openshift-origin-cartridge-ruby/bin/control
Merge pull request #3399 from smarterclayton/propagate_app_id_to_gears

Merged by openshift-bot
Add REST API docs to the Origin doc set.
Merge pull request #3511 from nhr/add-rest-api-to-doc-set

Add REST API docs to the Origin doc set.