Allow multiple ControlActions per Application

[alastair]

Many of our algorithms have multiple parts, and are configured with multiple different EntryPoints for each part. All of these parts should be connected to the same Application.

We could specify two arguments and 2 config files (e.g. --application app.ini --controlaction ca.ini), or use a different structure for the configuration (e.g. prefix multiple control actions in an ini file with a set prefix per part, or use json so that we can have structured config files)