Added CORS Support

• Added CORS support to ApiPresenter. Available options:
  • 'auto' - send back header Access-Control-Allow-Origin with domain that made request
  • '*' - send header with '*' - this will work fine if you dont need to send cookies via ajax calls to api with jquery $.ajax with xhrFields: { withCredentials: true } settings
  • 'off' - will not send any CORS header
  • other - any other value will be send in Access-Control-Allow-Origin header
• Rewritten few internal functions