Loading i18n layers produced by dojo <= 1.9.2 with dojo > 1.9.2 results in fallback error.

[Clement Mathieu]

The back compatibility in nls preload does not have the good behavior.

The back compatibility is done here: ​https://github.com/dojo/dojo/blob/master/i18n.js#L377

// backcompat
bundle._localized = bundle._localized || {};

In back compatibility the behavior should be "skip the bundle improvement for now as we don't have information" (which is pre 1.9.3 behavior). But this is actually saying that there is no better bundle for this locale which may be wrong.

This is affecting versions 1.8.6+, 1.9.3+, 1.10.0+

[Clement Mathieu]

I submitted a PR to solve this issue: ​https://github.com/dojo/dojo/pull/148