Resolve some issues associated with loading and updating bundles
Resolve some issues associated with loading and updating bundles

Namely:
* Avoid fetching translations while already fetching translations by streamlining bundle loading logic
* Be smarter about handling bundle updates - if current bundle is an API bundle and it has no locales known - fire off a sync; when sync finishes, we re-enter the update and this time - check if we need to fetch locale data and go from there...
* Always update reusable strings, unless we fired off a sync and waiting for localization data - when updating with bundle

This should solve issues with double fetching of files; not finding data that was fetched, etc...

translationexchange/tml-objc,translationexchange/tml-objc,translationexchange/tml-objc,translationexchange/tml-objc