Store Execution Properties in job file

It would be useful to be able to set up some of the job config files directly in a graph/jobflow and propagate it to the server. For instance, users would like to be able to set up max_running_concurrently=1 on desired graphs. The reasons behind this suggestion are:

• version control - the graph would be versioned with this desired job config property imanently,
• if the graph_file file path changes, the job config property gets lost.

As part of this, we renamed Job Config properties to Execution Properties