rMOZILLACENTRAL0aa10e365245

Bug 1467359 - Implement fetch-url jobs using a transform; r=tomprince

Previously, the fetch kind was defined by a job "using" flavor.

An upcoming commit will need to derive new tasks from fetch job
definitions. In order to do this, we require a transform. And
this transform would need access to the original data from the
job description. But by the time the "using" transform runs, a
lot of this data is thrown away. It would be possible to stuff
the meaningful metadata inside attributes on the created…