ObjFW  Changes To API Review for 1.0

  * ❌ OFMutableZIPArchiveEntry.m
  * ❌ OFMutex.m
  * ❌ OFNonretainedObjectValue.m
  * ❌ OFNotificationCenter.m
  * ❌ OFNull.m
  * ❌ OFNumber.m
  * ❌ OFObject+KeyValueCoding.m
  * ❌ OFObject.m
  * ✅ OFObject.m
  * ❌ OFOptionsParser.m
  * ❌ OFPBKDF2.m
  * ❌ OFPlugin.m
  * ❌ OFPointValue.m
  * ❌ OFPointerValue.m
  * ❌ OFPollKernelEventObserver.m
  * ❌ OFRIPEMD160Hash.m