* lily/simple-spacer.cc: Remove class Simple_spacer_wrapper.
Replace it with functions get_line_forces and get_line_configuration.
(class Simple_spacer): Make data private.
Rewrite compression algorithm to be faster and simpler.
* lily/simple-spacer-scheme.cc (ly_solve_rod_and_spring_problem):
* lily/gourlay-breaking.cc (solve):
* lily/constrained_breaking.cc (space_line):
Change it to the new simple-spacer code.
* lily/paper-score.cc (get_paper_systems):
(Paper_score):
(process):
Delay breaking the systems until they are requested.
(find_break_indices):
Use vsize for indices.
(calc_breaking):
Move the "Calculating line breaks" message here.
* lily/system.cc (pre_processing):
Move the "Calculating line breaks" message away from here.
(break_into_pieces):
Allow multiple calls to this function in sequence (with touching-but-
not-overlapping breakpoints).
* lily/constrained-breaking.cc:
Replace most of the get_XXXX functions with get_line_details.
Only calculate the force for each line. Calculate configurations only
for the lines we will actually use.
Replace cols_ with lines_.