ObjFW  Changes To API Review for 1.0

  * ✅ OFData+MessagePackParsing.m
  * ✅ OFData.m
  * ✅ OFDatagramSocket.m
  * ✅ OFDate.m
  * ✅ OFDictionary.m
  * ✅ OFEmbeddedFileURLHandler.m
  * ✅ OFEpollKernelEventObserver.m
  * ❌ OFFile.m
  * ✅ OFFile.m
  * ❌ OFFileManager.m
  * ❌ OFFileURLHandler.m
  * ❌ OFGZIPStream.m
  * ❌ OFHMAC.m
  * ❌ OFHTTPClient.m
  * ❌ OFHTTPCookie.m
  * ❌ OFHTTPRequest.m