* ly/performer-init.ly (ScoreContext): add Timing alias

* ly/performer-init.ly (ScoreContext): add Timing alias

* lily/translator-def.cc (Translator_def): copy alias list too.

* lily/stem.cc (height): add half beam thickness for beamed stems.
This fixes tuplet bracket vertical offsets on beams.

* lily/text-spanner-engraver.cc (stop_translation_timestep): small
cleanups; only hang spanner on paper-columns if there are no
note-columns to hang on. Also hang finished spanner on the last
note.

* lily/tuplet-bracket.cc (calc_position_and_height): only quantize
inside staff.