* Renamed fplainn::Channel::destroyIncompleteChannel to removeIncompleteChannel.
  ^ No longer deletes the incomplete channel. Simply removes it from its list.
  ^ Introduced a new operator delete() custom operator, that will safely delete
    all derivatives of fplainn::Channel, as long as they are deleted via a
    pointer/reference to an fplainn::Channel.
    ^ Might want to force the issue and also overload operator delete in the
      derived classes as well.

* Solved a design issue caused by the fact that we were re-allocating the
  incomplete channels to create base-class Channel derivative objects.
  ^ The problem is that udi_channel_spawn will return a handle to a channel
    even before both ends have been matched up.
  ^ So the pointer we return while the channel is incomplete must also be
    valid after it has been completed.
  ^ Had to stop reallocating, and just downcast.