VendorExtensions are not parsed properly

in case an object property is defined as a $ref and has vendor extensions, the extensions are ignored during parsing. The same happens for arrays.

swagger: '2.0'
info:
  description: 'Good'
  version: '2.0.0'
  title: 'Test'
paths:
  /foo:
    post:
      responses:
        200:
          description: 'OK'
definitions:
  Interval: 
    type: object
    properties:
      start:
        type: number
        x-custom: true
      finish:
        type: number
      distance_type:
        type: object
        properties:
          name:
            type: string
            x-custom: true
  Distance: 
    type: object
    properties:
      interval:
        x-custom: true //<- HERE
        $ref: "#/definitions/Interval"
  Run: 
    type: object
    properties:
      distance:
        x-custom: true
        $ref: "#/definitions/Distance"
  Competition: 
    type: object
    properties:
      runs:
         x-custom: true
         type: array
         items:
           $ref: "#/definitions/Run"

x-cusom in Run->Distance, and Distance->Interval are lost

The patch is attached.

Issue_#798_fix_parsing_vendor_extensions_in_case_of_an_object_is_defined_as_$ref_and_array.patch.txt

No source file or test is named in the issue. Start by reproducing the supplied Swagger YAML and trace parsing of $ref properties and array items; done means the x-custom extensions on the referenced object and array cases are preserved rather than ignored.