szablon: don't duplicate TextScripts
szablon: move helper files to subdir
szablon: allow compiling parts and score independently

I want to be able to compile parts independently from score,
just from within part files. Until recently this was simple -
parts contained just a staff with respective part, and compiling
such file results in a part (while including it together with
others can result in combined score).

Unfortunately, to faciliate partcombining i had to define
some additional functions in each file that was meant to be
compiled, and that breaked the structure - you can't
\include a function definition directly into \score block.

Now this is done by using a separate "part-solo.ly" file
that just compiles one part.  The interface is kept clean
by using Frescobaldi's masterfile command.
szablon: use Devnull context for a2 fragments

until now, when two voices were in unison for some passage,
i tried to hide one of them (to avoid duplicate notes and
symbols from being printed).  This was unsatisfactory, as:
 - some elements (e.g. augmentation dots) were positioned
   wrongly (i.e. they were taking hidden voice into account)
 - there was a lot of unwanted warnings about note collisions

using devnull context solves this - it simply erases the
unwanted part totally.
szablon: list todos for new pieces
szablon: small reword
szablon: support voice division in midi
Ave Maria: wstaw pusty szablon LilyPondowy
Ave Maria: ilustracja zamiany metrum dla Zuzi
Ave Maria: cofnij przykład 12/8 dla Zuzi
Alleluja Chwalcie Pana: dodaj szkielet LilyPondowy
dodaj prosty szablon LilyPondowy
Ave Maria: popraw łuk sylabiczny w sopranach t.2

Jestem pewien, że zapis oryginalny to błąd edycyjny,
bo żadne miejsce w reszcie utworu nie zawiera podobnego
dziwnego zapisu.
przenieś Alleluja chwalcie Pana do osobnego folderu
Ave Maria: dodaj pierwsze takty w pozostałych głosach (ATB).
przepisywanie: dodaj folder "LilyPond - pomoce" i instrukcję
Ave Maria: dokończ partię sopranu (Marlena)

korekty będą zapisane osobno.
Ave Maria: korekta sopranu

zastosowanie pauz całotaktowych (R),
poprawa zlegowanych fis i gis na przedłużone f i g.
Ave Maria: sopran - popraw formatowanie
Ave Maria: sopran, dokończenie korekty