Functionality offloads possible:

FruitySeqEventInput:
   Most functions:   seqevent

FruitySeqRollInput:
   Most functions:   seqroll

mainwid:
   seq_from_xy()
   on_button_release_event(), possibly:

      perf().new_sequence(current_sequence());
      *(perf().get_sequence(current_sequence())) = m_moving_seq;

      perf().new_sequence(m_old_seq);
      *(perf().get_sequence(m_old_seq)) = m_moving_seq;

      There may be some other small perform formulas to encapsulate.

mainwnd:
   Perform functionality already mostly offloaded.
   There may be some other small perform formulas to encapsulate.


