Cleaned up ScorePackageManager main menu.

OLD:

    Score (2014)

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

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

NEW:

    Score (2014)

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

Everything works as before.

Just removed redundant navigation commands from menu.