async import translators

[Emiliano Heyns]

I'm trying to figure out how async import translators (those with configOptions.async set to true) work.

1. Does the async: true only relate to the import? If a translation does both import and export, export is still sync right?
2. When configOptions.async is set to true, item.complete() always returns a promise, correct?
3. Promise.coroutine does not seem to be available in the translators. Can it be made available?
   
4. If Promise.coroutine would be available, would it be largely sufficient to yield on item.complete() instead of just calling it in doImport to make a translator async?
5. How do async translators import collection info? The collection info is tied to the references to be imported using itemIDs that are only meaningful for the duration of the import session. Will this mechanism stay unchanged, even when the items will now not be saved in bulk at the end of the session?