make all boards in reading configurable for locale, and use this and the global locale configuration.
add enabling sound in conf for smallnumber (the two boards) and use locale_sound in this case.
disable wordlist button as is not ready for the coming release
clean login.py trace
clean get_conf trace in gcompris_db
add wordlist.h wordlist.c: preparation of api for getting wordlist xml files. Not used in the coming release.