Right now, each time we add new language or new charset support, we have
too many pieces of code not to forget to edit. The script
script/BuildLangModel.py will now take care of the main parts: listing
the sequence models, listing the generic language models and computing
the numbers for each listing.
Furthermore the script will now end with a TODO list of the parts which
are still to be done manually (2 functions to edit and a CMakeLists).
Finally the script now allows to give a list of languages to edit rather
of having to run it with languages one by one. It also allows 2 special
code: "none", which will retrain none of the languages, but will
re-generate only the new generated listings; and "all" which will
retrain all models (useful in particulare when we change the model
formats or usage and want to regenerate everything).
Adding generic language model (see coming commit), which uses the same
data as specific single-byte encoding statistics model, except that it
applies it to unicode code points.
For this to work, instead of the CharToOrderMap which was mapping
directly from encoded byte (always 256 values) to order, now we add an
array of frequent characters, ordered by generic unicode code points to
the order of frequency (which can be used on the same sequence mapping
array).
This of course means that each prober where we will want to use these
generic models will have to implement their own byte to code point
decoder, as this is per-encoding logics anyway. This will come in a
subsequent commit.
