Better String Resource / Translation support

[fennifith]

Currently, unless otherwise specified, all data specified in an app's config file is replaced with the versions of that data fetched from github unless otherwise specified. However, the github versions of that data cannot be translated (as I'm pretty sure the github api only provides information in one language at a time, and most people do not write their bios in more than one language). Ideally, there would be a way to only fetch data from github for one language, and use the translated strings for the rest. This would require some extremely weird syntax in the config file though. Maybe something like bio="^(lang != en)@strings/someone_bio" to specify that the string should only be overwritten if the current locale is set to en. The lang != part isn't necessarily needed, but it improves readability and I might need to use the same or similar syntax elsewhere in this project later on.