Added support copy-files directive

Added copy-files for modules and project:
File

{
  "extra": {
    "copy-files": {
      "enyo/dropzone/dist/min/dropzone-amd-module.min.js": "public/js/vendor/dropzone-amd-module.min.js"
    }
  }
}

Directories

{
  "extra": {
    "copy-files": {
      "twbs/bootstrap/dist/js/": "public/js/vendor/",
      "twbs/bootstrap/dist/css/": "public/css/",
      "twbs/bootstrap/dist/fonts/": "public/fonts/"
    }
  }
}

Simplify modules structure

Just copy modules files to application directory
Updated migration