- no longer forces default inchannels and outchannels, and lets the
  AdjustedMatrix.process() method "do the right thing" if neither is
  explicitly set by the user
- some mostly aesthetic changes that more cleanly separate the vector
  and scalar (F) adjustements
- modified AdjustedAlgorithm.can_produce_data():
  a. if any non-F inchannels cannot produce data, return False
  b. if F inchannel can produce data, return True as long as all
     non-F inchannels can also produce data
  c. if this is not desirable (e.g., you want to treat non-F and F
     channels independently), it is necessary to create two instances
     of AdjustedAlgorithm, one for non-F inchannels, and one for F.