Revisiting Serbian Latin

Hi Polyglots!

I’d like to reopen discussion on adding a discrete Serbian Latin locale. We seem to have last addressed it in 2012. I think it’s worth considering adding here circa 2017 for a few reasons:

1. We now are in a very async world (eg, JS callouts) and the transformative plugins that tend to be suggested do not handle asynchronous pieces well. We see the problem with Jetpack Comments (as noted by eboye previously) but the same issue presumably extends to any theme or plugin making async calls.

2. Conceptually, IMHO, having a discrete entry designated is the “right thing to do” programmatically. It helps dependencies (plugin, theme, etc, as noted in 1) be accurate which concretely ends up meaning less bugs.

3. Official GP variant support is coming so we might as well be prepared.

4. `de-formal` established a discrete variant precedent.

5. A Serbian Latin GP project should require no additional validation resources as we could simply cron job transliteration of Cyrillic to the Latin project every few hours.