Descriptor no longer calls describeMatch() or joiner()
Descriptor subclasses: remove obsolete joiner() methods
Value classes: remove obsolete describeMatch() method
INTEGRATE: Remove obsolete describeMatch() and joiner() methods

* dev:
  Value classes: remove obsolete describeMatch() method
  Descriptor subclasses: remove obsolete joiner() methods
  Descriptor no longer calls describeMatch() or joiner()