* scm/output-ps.scm (output-scopes): use ly:paper-lookup for font

* scm/output-ps.scm (output-scopes): use ly:paper-lookup for font
props.

* input/test/tie-sparse.ly: remove.

* lily/tie-performer.cc (try_music): copy & paste from
Tie_engraver.

* lily/music-output-def.cc (LY_DEFINE): bugfix. Don't do
variable_ref twice.

* lily/key-performer.cc (create_audio_elements): use
alterations-in-key.

* scm/midi.scm (accidentals-in-key): divide alterations by 2.