[data processing] Add data sources from job launch

[Chad Roberts]

*wishlist for juno*

As discussed at the Atlanta design summit, the launch job dialog prompts the user to select data sources to use as input and output for the job. As a user, it is easy to forget to create those data sources ahead of time and it's annoying to have to back out, create them and then go back to the job and start the launch process again.

It was suggested that the select boxes for inputs be changed to include the [+] button that will allow the user to create a new data source 'on-the-fly' for use in the job launch and in the future.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/109671

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/109671
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=56334472d609f586d6d6729e62ee1f5b710b5896
Submitter: Jenkins
Branch: master

commit 56334472d609f586d6d6729e62ee1f5b710b5896
Author: Chad Roberts <email address hidden>
Date: Fri Jul 25 14:19:34 2014 -0400

    Ability to create data sources from job launch

    Adding the ability to generate data sources from
    within the job launch modal.
    * Change to DynamicChoiceField for input and output
    * Changed workflow for data source to properly set
      workflow.object

    Change-Id: I7d3b7bbd94c50f5e70a7e70bdb6d4a86475e1a6e
    Closes-Bug: #1346931