fix for current level-sublevel codec

[mvayngrib]

see if these changes make sense to you. An undesirable but alternative option is to require('level-sublevel/legacy')

[thlorenz]

they use the raw level

how can we use that in order to dump all?
afaik we can get access to the underlying db from sublevel. It doesn't matter how, but we need to get the dump.all functionality working before pushing another release.

[thlorenz]

Ah NM, I see you fixed it?
If those tests pass I'm happy :)