Include some default information in control.json?

[cmccoy]

It might be nice to have some standard values, like the root of the nestly run, and the directory the control.json file is getting dumped to in every control.json file generated by nestly, either in the top level, or in a special nestly place, like:

{
  "_nestly": {
    "output_path": "/path/to/root/value1/value2"
  }, 
  "param2": "value2", 
  "param1": "value1"
}