Add the ability to strictly localize by either just language or country

In some cases, you might want to make a new change in a language, like English and apply that to all locales using English. For example: en-US, en-CA, en-MX, etc. It would be nice to have something built in to easily port all those changes in a single shot, especially if you have something like 40 locales using English.

Conversely, you might have circumstances where you want to make a change in a country, like the United States and apply it to all locales in the United States in a single shot. For example, en-US and es-US.