Bug 1065523 - Part 0: enable KitKat-specific code in locale picker. r=nalexander
Bug 1065523 - Part 1: locale picker screen displays short locale display name, not capitalized region-decorated name. r=nalexander

What I think was happening here: we were taking a locale *tag* ("en-US") and giving it to the Java Locale constructor to parse. It parsed that as "en" (because it expects _ not -), so we'd get "English".

And because it was the display string from the locale, in e.g., French we'd get "français", lowercase.

The fix is to just use the same code path that we use for the list picker itself -- make a descriptor from the tag, and ask it for its display string.