* scm/paper.scm (set-staff-size): new function: set default

* scm/paper.scm (set-staff-size): new function: set default
staff-size.

* scripts/convert-ly.py (conv): add conversion rule.

* lily/music-output-def.cc (LY_DEFINE): ly_output_def_scope: new
function.

* scm/paper.scm: new file.
(set-staff-size): new function
(set-paper-size): new function

* lily/parser.yy (music_output_def_body): restructure definition,
so first Scheme statement in \paper also happens in new scope.

* lily/system.cc (post_processing): move uniquify_list () to
dumping molecule stage.

* ly/engraver-init.ly (AncientRemoveEmptyStaffContext): set
barCheckSynchronize to #f. Warning: this will mess up scores that
use barchecks to shorten measures.

* mf/feta-bolletjes.mf (overdone_heads): make note heads rounder
at 20pt too.

* Documentation/user/tutorial.itely (Printing lyrics): document
\lyricsto

* lily/my-lily-lexer.cc: \newaddlyrics -> \lyricsto

* Documentation/user/refman.itely (Fermatas): document \lyricsto

* lily/new-lyric-combine-music-iterator.cc (process): don't crash
if Voice is not found.

* VERSION: release 2.1.10

* lily/parser.yy (markup): MARKUP_HEAD_EMPTY

* lily/system.cc (output_lines): revert uniquify_list() patch,
strange side effects seen.