* scm/define-context-properties.scm

* scm/define-context-properties.scm
(all-user-translation-properties): remove verticalAlignmentChildCallback

* lily/tuplet-bracket.cc: use positions property iso. left,right-position.
(calc_direction): use callback
(calc_positions): use callback.

* lily/tie.cc (calc_direction): use callback. Only call parent
positioning for more than one tie.

* lily/tie-column.cc (calc_positioning_done): use callback

* lily/slur-scoring.cc (calc_control_points): use callback

* lily/slur.cc (calc_direction): use callback.

* lily/note-collision.cc (force_shift_callback): remove.

* lily/dot-column.cc (force_shift_callback): remove. Use
other_axis_parent_positioning.

* lily/grob.cc (other_axis_parent_positioning): new function.
(same_axis_parent_positioning): new function

* lily/align-interface.cc (alignment_callback): remove function.

* lily/note-collision.cc (calc_positioning_done): use callback.

* lily/laissez-vibrer-tie.cc (calc_control_points): use callback.
(calc_direction): idem.
remove print function.

* lily/laissez-vibrer-tie-column.cc (calc_positioning_done): use callback.

* lily/dot-column.cc (calc_positioning_done): use callback.

* lily/break-align-interface.cc (calc_positioning_done): use callback.

* lily/beam.cc (calc_direction): use pseudo-property for beam
direction callback.
(calc_positions): use callback

* lily/align-interface.cc (calc_positioning_done): use
callback. Fold fixed  distance and normal alignment in one function.

* lily/stem.cc (calc_stem_end_position): use callback.
(calc_positioning_done): idem.
(calc_direction): idem.
(calc_stem_end_position): idem
(calc_stem_info): idem.

* lily/grob-property.cc (get_property_data): new function:
(try_callback): new function.

* scm/define-grob-properties.scm (all-user-grob-properties): doc
callbacks property.

* lily/break-align-interface.cc: remove Break_align_interface::alignment_callback.