Add method to get config file

[tonyganch]

TL;DR: Here I propose adding comb.getConfig('csscomb') method.

I spent some time playing with csscomb and node and found getting a default config file inconvenient.
Consider two examples: installing as a project dependency and globally.

• npm install csscomb

var Comb = require('csscomb'),
    config = require('./node_modules/csscomb/.csscomb.json'),
    comb = new Comb();

comb.configure(config);
comb.processString(someString);

I find it strange that user should know where exactly to find a config file, so every time we move it to another directory (or rename it), we make a new version incompatible with a previous one.

But it’s even more amusing when the module is installed globally.

• npm install csscomb -g

var Comb = require('csscomb');

Now what? How can I find that config file?
If I have all needed permissions and symlinks are supported, I can run npm link:

var npm = require('npm'),
    config;

npm.load(function (er, npm) {
    npm.commands.link('csscomb', function() {
        // Now we have "a local copy" of the module:
        config = require('./node_modules/csscomb/.csscomb.json');
    })
});

The problem with knowing where to look is the same as with local installation.

And what if user/process doesn’t have necessary permissions?
I managed to use exec:

var exec = require('child_process').exec;

exec('which csscomb', function () {
    // Use the path to go to node_modules folder
});

So many difficulties just to get one file from our package.

Why don’t we make a method like getConfig() that will make everything easy?
We can get the file by its name:

// Default one:
var config = comb.getConfig('csscomb');
// Zen from php version:
var config = comb.getConfig('zen');

Or, related to issue #102:

// Make new instance and configure in one line:
var comb = new Comb('csscomb');