Restructured configuration system

Configuration logic from node-debug.js moved to config.js
node-debug receive configuration from rc now
config uses yargs argv preprocessor now
Removed conversion part of config.js
Fixed hight priority of node-debug hardcoded defaults
Fixed default web host for node-debug
  (`127.0.0.1` instead of `localhost`)
Fixed null value of web host
  (default web host is empty string now)
Added script option
Added list of avaible options as default help info
That way you are still duplicating the following two lines:

```js
  var dashedKey = keyToDashedKey(key);
  var definition = definitions[dashedKey];
```

The `Config.filterOptions` function makes sense, you need to add another one to prevent duplication of those two lines.