Run the genlang.py script from the top level wxWidgets directory to
update include/wx/language.h (wxLanguage enum), interface/wx/language.h
(its documentation) and src/common/languageinfo.cpp (conversion tables)
with the data from langtabl.txt and scripttabl.txt.

langtabl.txt contains a tabular list of language entries. Each entry
contains

- a symbolic language identifier used in enum wxLanguage,
- a BCP 47-like locale identifier,
- a Unix locale identifier,
- a Unix locale identifier including a region id (if the default Unix
  locale identifier does not include a region identifier) (mainly for
  compatibility with wxWidgets version below 3.1.6),
- numeric Windows language identifier (1),
- numeric Windows sublanguage identifier (1),
- language and region description in English
- language and region description in native language.

scripttabl.txt contains a list of 4-letter script codes and their
aliases (English) based on the ISO 15924 standard (2), restricted to
entries for which aliases are defined. This list is used in wxWidgets
to convert between script code used in BCP 47-like identifiers and
script modifiers used in Unix locale names. The data in (2) can be used
to update scripttabl.txt if necessary.

(1) used on Windows only, deprecated by Microsoft
(2) http://www.unicode.org/iso15924/iso15924-codes.html
