SourceContext improvements

* When loading from multiple files, ensure that the correct filename
  is included in the path (rather than just the last).
* Keep track of the line number where jobs are defined and include it
  in the job representation.  This is used in the inheritance_path
  var to aid in debugging.

Change-Id: Ia3f0d03cd45d6c3b24b3dc7b663d1175cc0a18fc
2 files changed