[bug-gettext] Improve plural rules detection

[Michele Locati]

When invoking msginit, we call cldr-plurals by passing to it the
language code, extracted from the locale code by the
language_of_locale funciton.

This may lead to some issues.
For example, if the locale code is pt_PT, the language code will be
pt, but the CLDR plural rules for pt and for pt_PT are different (see
https://unicode.org/repos/cldr/tags/release-35-1/common/supplemental/plurals.xml
).

So, what about passing to cldr-plurals the locale code instead of the
language code, and letting cldr-plurals look for the applicable rule?

The attached patch implements that.
In particular, if for example the locale ID is it_IT, cldr-plurals
will look for pluralRules XML nodes with the locales containig
"it_IT". If no such node exists, cldr-plurals will look for "it".

--
Michele

0001-Improve-plural-rules-detection.patch
Description: Binary data