Add blacklist for locales  (#309)

This is for issue #309. I added here the changes for the pulse script and also the blacklist for staging beta and release, for testing. So as discussed, the blacklist will have priority when there are both.
Well, then we also need no blacklist for the staging config. In that environment we only run a limited set of locales, here en-US only. So the changes as done in this PR already include a whitelist AND a blacklist.

In any case, both features will remain in the script file even they are not used simultaneously. Checking both lists I would call a feature here, also for safety. Keep in mind that having both lists e.g. for email filters is pretty common. BL is for definitive spam, and WL for always pass through. Everything else is handled by clients, which we don't explicitly have here. 

Means we could leave the blacklist check in the white-list check, but it feels a bit off the place for me.