Describe the bug
When exporting annotation with Flashcard, the JSON line is undefined

    },
    undefined,
    {

To Reproduce
Steps to reproduce the behavior:

1. Annotate a line of text
2. Add a Flashcard with data on back and front
3. Export annotation as JSON
4. Search "undefined" you should get to that badly exported entry

Expected behavior

Fla

When I start Anki 2.0, "Your Incremental Reading settings file has been modified for compatibility reasons. …", and my custom QuickKey is not there when I start Anki 2.1 after that.

We currently overwrite CollectionStats.todayStats in order to allow users to define a custom maturity ivl. This can cause conflicts with other add-ons that patch the same method.

We should investigate if this approach is actually still necessary. For starters, we should look into conditionally overwriting CollectionStats.todayStats only if a non-defaut MATURE_IVL is set.

(Thanks to Gus