Implement Data Dispatcher and (if needed) MetaCat

[LTrestka]

Experiments will be using MetaCat and Data Dispatcher in the future for defining projects and metadata. Thus POMS needs to have Data Dispatcher (and possibly metacat) implemented at the campaign level (user selects SAM or Data Dispatcher at creation time). We can do this via bash tools, or a Python API (preferred) which shares many similarities to our current SAM implementation.

POMS should have a data dispatcher client that can be used to perform a similar work flow as SAM does today:

• Data Dispatcher authentication should be handled via tokens, not x509.
• Include new class objects and handler methods to support DD operations.
• Job submission needs to run the appropriate scripts to launch DD projects.
• Submission broker (or new broker) needs to be able to monitor the status of DD projects.
• Pages should be able to display campaign details, processing status, and file information of DD project campaigns.

[LTrestka]

In develop branch, awaiting testing by experimenters