Add line numbers to auto-detected configs.

The simplest way to implement this was to use the loc:true option of
EsprimaJS which includes line and column number data to each AST node.
Unfortunately the data is rather large, especially when you compare it
to the compact "range" data:

    {
        "type": "SomeNode",
        "loc": {
            "start": {"line": 2, "column": 5},
            "end": {"line": 8, "column": 12}
        },
	"range": [28, 16]
    }

Sadly, having this enabled drags down performance quite drastically.
Parsing full src/ dir of Sencha Touch before and after this change:

before: 4.5 seconds
after:  7.9 seconds