Cleanup and pep8 fix.
Add splitted POST sync design docs (#5571).
Split sync in multiple POST requests in server (#5571).
Split sync in multiple POST requests in client (#5571).
Allow for interrupting and recovering sync (#5571).
Add sync status signals (#5517).
fix allow interrupt in target client
Properly raise when couch db does not exist.
Fix tests for new sync process.
Fix stuff from kali's review.
Turn SQLCipher.sync_state into a ClientSyncState instance.
Merge remote-tracking branch 'refs/remotes/drebs/feature/5517_split-sync-post' into develop
Use a fresh resource for multipart puts (#5739).
Fix package build script.
Add password option to client db script.
Remove close_connections() from tests.
Replace client sync state by a sync_id.
Make server auth time-insensitive.
Add changes file.
Reset synchronizer state in order to reuse the same synchronizer multiple times.