move names() calls into the for loops, add return to namespace_names
amend l10n_parser.r's URL retrieval function to export the language codes, which can then be reused elsewhere for language parsing.
add dlply() call to break down the data and provide discrete, per-namespace lists of unique names (in a regex-able form)
remove the initialisation of an unneeded list from l10n_parser.r
create a list of language_prefixes.vec and unique_by_namespace.ls, for returning.