Remodel soledad u1db couchdb backend so it's concurrent.
- Store a u1db document's conflicts and transactions inside the couch document.
- Use couch's view and list functions to retrieve metadata.
- Use couch update functions to selectivelly insert metadata, as sync and transaction info.
- Find a way to handle indexes wisely.
(from redmine: created on 2013-11-13, closed on 2013-12-19)
- Relations:
- precedes #4451
- child #4680 (closed)
- child #4682 (closed)
- child #4683 (closed)