For example, to determine whether the Japanese or Chinese form should be shown.
* Dictionaries.lua - use iso3 codes everywhere
readerdictionary.lua - convert iso to bcp tag, to construct ifo_lang
isolanguage.lua - map from iso3 to full language name, map from iso3 to bcp language tag
* Make the full language names translatable
* Store ifo information from dictionaries.lua in downloaded dictionaries
