Improved Autoeditor menuing.

Example:

    Red Example Score (2013) - materials

       1: instrumentation (AE)
       2: magic numbers
       3: pitch range inventory (AE)
       4: tempo inventory (AE)
       5: time signatures

          materials - copy (cp)
          materials - new (new)
          materials - remove (rm)
          materials - rename (ren)

    > instr

    Red Example Score (2013) - materials - instrumentation (AE)

       1: output.py
       2: __init__.py
       3: __metadata__.py
       4: versions/

        * hornist: horn
        * trombonist: tenor trombone
        * pianist: piano
        * percussionist: no instruments
        * violinist: violin
        * cellist: cello

          material - autoedit (ae)
          material - illustrate (i)

          output.py - check (oc)
          output.py - open (oo)
          output.py - write (ow)

    > ae

    Red Example Score (2013) - materials - instrumentation (AE)

          EDIT:

       1: hornist: horn
       2: trombonist: tenor trombone
       3: pianist: piano
       4: percussionist: no instruments
       5: violinist: violin
       6: cellist: cello

          elements - add (add)
          elements - move (mv)
          elements - remove (rm)

          done (done)

    > q