Some locale codes in eZ Publish are wrong according to definition, see below. We should fix them. Note backwards compatibility - should we only deprecate them and make the new ones as copies?

The current kernel does not allow us to code all locales correctly. This is what we currently support:
language-COUNTRY.charset@countryvariation
For example eng-GB.utf8@euro, which means english, as spoken in the UK, in the utf-8 charset, using the 'euro' countryvariation (presumably using the euro instead of GBP). Countryvariation is only used for locales. It can not be used when fetching translations. See eZLocale::localeInformation() and eZLocale->TranslationCode.

For serbian, there are two translations, using the same language and country (srp-RS), but different alphabets (latin and serbian cyrillic). Charset is irrelevant here. Thus, we cannot support serbian using our current locale codes.

Suggestions:
1) Change the kernel code to support countryvariations in translation names (i.e. srp-RS and srp-RS@latin). Then we can keep the existing locale code rules.
2) Change the locale code rules to allow variations in the language (i.e. srp-RS and srplatin-RS). Then we can keep the existing kernel code.
3) Extend the locale code rules to include alphabets, i.e. language@alphabet-COUNTRY.charset@countryvariation or, to be backwards compatible: language-COUNTRY.charset@countryvariation@alphabet

I like 1), it seems clean although this is not the originally intended purpose of countryvariations. We can make it backwards compatible by making it fall back to swe-SE when swe-SE@euro is not found among the translations.

The following locale changes must be done to be consistent with the standards:

cro-HR -> hrv-HR
ell-GR -> gre-GR
nor-NO -> nob-NO (Norwegian Bokmål) [1]
ser-SR -> srp-RS@latin [2]
cyr-SR -> srp-RS (Cyrillic)
slk-SK -> slo-SK
esl-ES -> spa-ES (Spanish, Castilian)

Both SVN and ez.no must be updated. Furthermore, we must confirm that the locale variation syntax (srp-RS@latin) actually works with languages. So far it has AFAIK only been used for locales.

ISO 639-2 (languages)
http://en.wikipedia.org/wiki/List_of_ISO_639-2_codes
Following the bibliographic (B) rather than the terminology (T) here, i.e. for chinese, "chi" rather than "zho".

ISO 3166-1-alpha-2 (countries)
http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2

[1]
There is no single standard norwegian, so nor-NO should not be used.
http://en.wikipedia.org/wiki/Norwegian_language

[2] Cyrillic is the official script:
http://en.wikipedia.org/wiki/Serbian_language#Writing_systems