Rachmaninoff Prelude Op. 23/2 prelim version

Basic typesetting done, many places need tuning.
Add accent adding function

New func to repeatedly add articulation to notes. Lots of accents across
the whole piece; hope it would be a (tiny) bit easier to read
afterwards.
Some slur and tuplet tuning, compress pages

Tons of trial and error with slur details parameter.
Reduced pages by default, if problems can't resolve this might be
reverted.
Replace some functions with tags

Some of the simplistic functions are just toggles that can be managed as
tags
Only set system-count for Lilypond <= 2.18.x

With 2.19.x, Lilypond renders best result on default setting, reducing
page count to 8, as well as fixing tuplet display problem.
Follow folder structure of existing prelude
Fix mutopia header, some indent change
Another batch of tuplet and slur tuning
Use tieWaitForNote for bar 23-24 tie
Merge branch 'rachmaninoff-prelude23-02' of https://github.com/abelcheung/The-Mutopia-Project
Metadata: Update Mutopia title to include "No. 1"
Header tweaks