Allow override of 'level' setting in project / syntax .sublime-settings file

[ollyollyollyltd]

This will allow users to set project specific phpcs rules for phpcbf to follow.

Use case:
I work on a single Drupal Project for which I want to use the Drupal coding standard. Globally I want to use PSR2. Currently I can only set the leve' parameter in my User phpcbf.sublime-settings file, but this will apply to all projects.

Here I can add a setting to my .sublime-project file:

{
    "settings": {
        ...
        "phpcbf.level": "/path/to/my/drupal-phpcs.xml"
    }
}

And only this project will use the Drupal standards.