Upated Tuning doctest.
Removed (nmm) command.

The command aliased 'materials - make new with manager'.

Materials menu now looks like this:

    Red Example Score (2013) - materials

        1: magic numbers (Red Example Score)
        2: pitch range inventory (Red Example Score)
        3: tempo inventory (Red Example Score)

        material - new by hand (nmh)
        material - new for editable mainline class (nmc)

    >

So the two available commands for making new material packages are (nmh) and
(nmc).

These will probably collapse to a single (new) command at some point in future.
Updated TODO.
Extended Transcript and TranscriptEntry.

You can now iterate the entries in a transcript:

    for entry in score_manager._transcript:
        ...

You can also now iterate the lines in a transcript entry:

    for line in score_manager._transcript[0]:
        ...

Implement a 'first_lines' property on Transcript. Example:

    >>> for line in score_manager._transcript.first_lines: repr(line)
    'Score manager - example scores'
    '> m'
    'Score manager - material library'
    '> nmh'
    'Package name> b'
    'Score manager - material library'
    '> q'

Use for writing tests.
Wrote test for making new material package.

The test makes sure that (b) works when getting package path.
Added 'is_in_user_input_getter' property to Session.
Extended Session.display_variables().

Method now hides next redraw when called in user input getter.

Example:

    Red Example Score (2013) - materials

        1: magic numbers (Red Example Score)
        2: pitch range inventory (Red Example Score)
        3: tempo inventory (Red Example Score)

        material - new by hand (nmh)
        material - new for editable mainline class (nmc)

    > nmh

    Package name> sdv
    command_history: ['ssx', 'red', 'm', 'nmh', 'sdv']
    controller_stack:
        ScoreManager()
        ScorePackageManager('/Users/trevorbaca/Documents/abjad/scoremanager/scores/red_example_score')
        MaterialPackageWrangler()
        <UserInputGetter (1)>
    current_score_package_manager: ScorePackageManager('/Users/trevorbaca/Documents/abjad/scoremanager/scores/red_example_score')
    hide_hidden_commands: True
    hide_next_redraw: False
    is_autoadding: False
    is_in_confirmation_environment: True
    is_in_editor: False
    is_in_user_input_getter: True
    last_asset_path: '/Users/trevorbaca/Documents/abjad/scoremanager/scores/red_example_score'
    scores_to_display: 'example'

    Press return to continue.

    Package name> q
Updated TODO.
Removed (nmh) command.

The purpose of 'materials - make new material by hand' (nmh) was to create a
new material package.

Use the 'materials - new' (new) command instead.
Merge pull request #373 from tiagoantao/master

more python 3 division issues
Renamed MaterialPackageWrangler method.

OLD: MaterialPackageWrangler.make_handemade_material_package().

NEW: MaterialPackageWrangler.make_new_material_package().
Updated TODO.
Implemented IOManager.make_subprocess() method.

Returns a Popen instance.
Integrated IOManager.make_subprocess() into Manager.
Updated TODO.
Removed 'material_manager_class_name'.

Was previously a piece of metadata inserted in some material package metadata
modules.

No longer needed.
Removed user_library_material_manaagers_directory_path property.

Removed from ScoreManagerConfiguration.

FILESYSTEM: you may remove any managers/ directory in your score manager
library.

No longer used.

Any collaterla housed in your managers/ directory can be moved to your makers/
directory instead.
Removed abjad_material_managers_directory_path property.

Removed from ScoreManagerConfiguration.

No longer needed.
Merge pull request #374 from tiagoantao/master

More div issues
Adjusted append_spacer_skip_to_underfull_measure style.