Comment #1 on issue 1879 by [email protected]: Packed-spacing works improperly with Mensural_ligature_engraver and Vaticana_ligature_engraver
http://code.google.com/p/lilypond/issues/detail?id=1879
mensural ligatures are better since 5cb09f71fea59c7bdbcb3c1dcb1151bbf19b4d26
