* lily/dot-column.cc (side_position): reach stem via dots-> head->stem.

* lily/dot-column.cc (side_position): reach stem via dots-> head->stem.

* lily/dot-column-engraver.cc (class Dot_column_engraver): excise
stem handling.

* lily/bar-number-engraver.cc (process_music): document function
of whichBar.

* lily/score.cc (default_rendering): add pscore, not systems
themselves.

* lily/paper-book.cc (get_system_specs): separate generation of
titles and systems.