Improved (rst) messaging.

Example:

    Red Example Score (2013)

       1: __init__.py
       2: __metadata__.py
       3: build/
       4: distribution/
       5: makers/
       6: materials/
       7: segments/
       8: stylesheets/
       9: test/

          build (u)
          distribution (d)
          makers (k)
          materials (m)
          segments (g)
          stylesheets (y)

    > rst
    Repository status for /Users/trevorbaca/Documents/abjad/scoremanager/scores/red_example_score ...
    # On branch master
    nothing to commit, working directory clean

    >