Set output file in .brackets.json

[thybzi]

It would be great to set output CSS path in the same place of .brackets.json

{
    "less": {
        "resources/less/main.less": "htdocs/css/main.css"
    }
}

Or even (see #72):

{
    "less": {
        "resources/less/*.less": "htdocs/css/*.css"
    }
}

P.S. I know that the same can be achieved by setting that in file:

// out: ../dist/app.css

But I think that storing such things in per-project config is much better practice

P.P.S. Maybe adding "files" subkey inside "less" key is more convinient for developing this feature

[jdiehl]

Related to #51