fixes https://anki.tenderapp.com/discussions/ankidesktop/15795-export
-error-doubling-br-tags
This code dates back a few years, and was probably a naive solution
for files breaking when exported with newlines. Ideally we should be
preserving the newlines and wrapping the field in quotes, but since
some people may be relying on exported files not to be quoted, we'll
wait to change this until the next major release. For now, we'll use
a space instead, which should not alter the appearance of the
rendered HTML.
- media syncing no longer locks the account, so it can be done
in the background in the future, and multiple clients can safely
sync media at the same time
- all operations are now idempotent, so they can be repeatedly safely
in the event of a connection error
- whether it's a normal incremental sync, an initial sync,
or the media database has been deleted, no files will be uploaded
or downloaded if they already exist on the other side
- file removals are now chunked like additions & updates, preventing
timeouts due to large requests
- if the server can't process a chunk in time, it will return a count
of what it did process, so the client can retry the rest
Notes for AnkiDroid:
- when porting this, recommend you pick a different name for the
.media.db2 file, so users don't accidentally copy the AD version to
the desktop or vice versa
- please make sure filenames are added to the zip in NFC form
