antiphonal: folder for helper scripts
psalter: rake: remove lists of psalms and canticles

these are instead loaded from the tex file
psalter: code generating versicles moved from rakefile to a separate script
psalter: all psalm occurrences labeled

now it will be possible to reference every occurrence of every psalm/canticle
and not only the first one

Important change: antifonar_zaltar.tex is now a generated file,
original input file is renamed to antifonar_zaltar.ltex
psalter: index of festal psalms: choose between instances of each psalm to avoid page-flipping

Up to now first occurrence of each psalm was referenced in the festal index,
which resulted to non-optimal suggestions.
e.g. for Good Friday's Laudes three distant places were suggested even if all the three
texts can be found in a single hour in the Psalter (Laudes, Friday of the 2nd week).

Now a simple, but in most cases successful algorithm is used to choose
which occurrence of a psalm present more than once in the Psalter to suggest for the particular
hour in order to eliminate unnecessary page-flipping and ribbons.

As a TODO remains to check if this algorithm is really ok as it is or if it results in any
harshly uncomfortable suggestion.
antifonar_zaltar.tex is now non-original, generated from antifonar_zaltar.ltex
check for groups of psalms following each other

in future they will possibly be replaced by a reference to an hour as a whole
refactor: move check producing output from a library to a script using the library