* lily/coherent-ligature-engraver.cc: fixed typo

	* lily/coherent-ligature-engraver.cc: fixed typo

	* lily/coherent-ligature-engraver.cc,
	lily/gregorian-ligature-engraver.cc,
	lily/ligature-bracket-engraver.cc, lily/ligature-engraver.cc,
	lily/mensural-ligature-engraver.cc, lily/note-heads-engraver.cc,
	lily/vaticana-ligature-engraver.cc,
	lily/include/ligature-engraver.hh, ly/gregorian-init.ly,
	scm/grob-description.scm: cleanup: junked LigatureHead grob and
	removed all ligature specific stuff from NoteHead code

	* lily/ligature-head.cc, lily/include/ligature-head.hh: removed;
	ligatures now use regular noteheads

	* lily/vaticana-ligature.cc: tiny code cleanups

	* lily/vaticana-ligature-engraver.cc: bugfix: insert additional
	space between two adjacent noteheads of the same pitch

	* scm/grob-description.scm: bugfix: VaticanaLigature: interface
	description; cleanup: removed obsolete font-family settings