Extensive multi-lang features

Stuff that’s missing for me:

• Syncing fields to origin (content gets taken over once, and then never again, see #529)
• Control separate publishing states for each language (some pages shouldn’t be available in every language, currently you can have one Status for all languages)
• Show that a field is translateable or not, also in the origin language
• Better hints on what language are you editing right now (it’s easy to miss that and edit in the wrong language)
• Changing the main origin, per page & lang (especially when having Region + Language Pages, this is important)

optionally control globally publishing state for each language, in order each single language can be set in state “draft” or “published” in its entirety (not only single pages).