Improved (va).

View inventory now saves to disk only in the case that view inventory has
changed during edit.
Cleaned up collection editor menuing.

OLD: two menu sections:

    Abjad IDE - scores - views (EDIT)

          elements - add (add)
          elements - remove (rm)
          elements - rename (ren)

          done (done)

    >

NEW: one menu section:

    Abjad IDE - scores - views (EDIT)

          elements - add (add)
          elements - remove (rm)
          elements - rename (ren)
          editing - done (done)

    >
Simplified signatures of Controller.invoke_python & Controller.invoke_shell().
Simplified AssetController.write_metadata_py() signature.
Distinguished between (rad) / (rad*), etc, for all repository commands.
Consolidated metadata menu commands.

Consolidate view menu commands.
Updated wrangler repository method names.

Added 'every_asset' to wrangler repository method names.

The new names make clear that the methods are starred methods.
Updated wrangler repository method test file names.
Harmonzied repository method names.
Improved (rcn*) messaging.

The method now accumulates all unadded assets and prompts the composer to
to confirm removal of all unadded assets at one time.

The method previously prompted the composer anew for each unadded asset.
Renamed keyword.

OLD: abjad_library=None.

NEW: abjad_material_packages_and_stylesheets=None.
Harmonized navigation method names.
Removed duplicated navigation tests.
Changed getter prompt.

OLD:

    Enter file name>

NEW:

    Enter file name]>

The prompt difference will be used passively to reinforce the (minimal)
differences in behavior between the getter environment and the other
environments implemented in the IDE.
Updated TODO.
Updated TODO.
Reinstated autoadding list elements. Use (add!) to begin.

Example:

    Abjad IDE - materials - test list (Bača) (EDIT)

          elements - add (add)
          editing - done (done)

    > add!
    Element]> 17
    Element]> 18
    Element]> foo
    Element]> bar
    Element]> done

    Abjad IDE - materials - test list (Bača) (EDIT)

       1: 17
       2: 18
       3: foo
       4: bar

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

    >
Improved (add!).

Menu now redraws automatically after every add.

Example:

    Abjad IDE - materials - test list (Bača) (EDIT)

          elements - add (add)
          editing - done (done)

    > add!
    Element]> 17

    Abjad IDE - materials - test list (Bača) (EDIT)

       1: 17

          elements - add (add)
          elements - remove (rm)
          editing - done (done)

    Element]> 18

    Abjad IDE - materials - test list (Bača) (EDIT)

       1: 17
       2: 18

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

    Element]> foo

    Abjad IDE - materials - test list (Bača) (EDIT)

       1: 17
       2: 18
       3: foo

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

    Element]> bar

    Abjad IDE - materials - test list (Bača) (EDIT)

       1: 17
       2: 18
       3: foo
       4: bar

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

    Element]> done

    Abjad IDE - materials - test list (Bača) (EDIT)

       1: 17
       2: 18
       3: foo
       4: bar

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

    >
Implemented elegant autoadd termination.

Description: use (add!) to begin autoadd. Use (foo!) to terminate autoadd.

That is, suffix any element with bang to termination autoadd, save the edited
collection and return to the collection main menu.

Example:

    Abjad IDE - materials - test list (Bača) (EDIT)

          elements - add (add)
          editing - done (done)

    > add!
    Element]> 17

    Abjad IDE - materials - test list (Bača) (EDIT)

       1: 17

          elements - add (add)
          elements - remove (rm)
          editing - done (done)

    Element]> 18

    Abjad IDE - materials - test list (Bača) (EDIT)

       1: 17
       2: 18

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

    Element]> 19

    Abjad IDE - materials - test list (Bača) (EDIT)

       1: 17
       2: 18
       3: 19

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

    Element]> 20!

    Abjad IDE - materials - test list (Bača)

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

          definition.py - autoedit (da)
          definition.py - check (dc)
          definition.py - open (do)
          definition.py - output (dp)

    >
Changed Controller.go_to_library() to Controller.go_to_top_level().