PM-746 parsing the dax should be a separate function to ensure no
leftover object references.
PM-746 Added logic in the parser to compute edges in the graph based
on the data dependencies between the jobs.
PM-747 changed the DAXParser callback initialization.
There is a separate initialization method, that takes PegasusBag as an
argument.
PM-746 use the logger to log messages in the callback.
PM-746 constant needs to be final.
PM-746 add depedencies once per new parent for a node.