* master:
Fix use of relative in docs and restore UTF-8 strings
compile fix (apparently)
Formatting nits.
Remove stray letter.
New dynamics engravers
Small formatting cleanups.
Add Drul_array<>::set() method.
Add ly:prob-[im]mutable-properties Scheme bindings.
Restore Tie direction default
Add NEWS entry for arpeggio.
Fix #455.
Fix #521.
Bump version.
Make fast_substitute_grob_array() protected.
Fix #434, #440
Add Skyline_pair::print[_point](), add some minor cleanups.
Move Skyline_pair and Paper_system bindings into their own files.
code layout nits.
Fix #578.