Alert Devs of missing Translations

[d4mation]

@joelworsham mentioned that as new Translations are being added to the Array in the Constructor, Devs should be alerted in a super obvious way that they need to update their Translations Array if there are ones that RBP Support expects to be there but are missing.

While RBP Support will still work without those additional Translations (And why it should only show to Devs), it would still be best if any Plugin that updates RBP Support is including up-to-date Translations.

Perhaps throwing a big ol' wp_die() if WP_DEBUG is enabled and there are missing translations? Or maybe just regular Exceptions? Maybe just add to debug.log?

[d4mation]

This is important in relation to #5. We can't just have the site kill itself if Translation requirements aren't met, but if we find a way to do it which only pertains to Devs that'd be fine.