Describe the bug
Right now, a user can set any arbitrary date, past or future for the start and finish dates of a ReadThrough. I think future dates are fine, but that it ought to prevent you from setting the finish date as earlier than the start date.

Expected behavior
The form should reject invalid dates and show error text on the page. Ideally it would check the dates before form

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.

The following methods/functionality need to be tested:

• Test that findById() successfully returns the correct CustomShelf when a valid ID is passed in
• A null pointer exception is thrown if a null CustomShelf is pased into delete()
• A custom shelf can be successfully deleted
• findAll() gets all custom shelves
• findAll(String shelfName) returns a list of all custom shelves if