Allow JSONFields to be modified through the admin UI.
At times, people would try to set new content in a JSONField in the

admin UI, since the field is editable. This resulted in a broken

encoded string that had to be literal_eval'd. It was also pretty easy to

accidentally lose the payload by introducing JSON syntax errors without

any warning.
Now a JSONField will store the string as-is if one is passed, instead of

assuming it's structured data it needs to be encoded and stored. To

ensure the data it's trying to set is valid, it also runs a validator

that guarantees input going in is valid JSON. Invalid JSON will result

in a validation error in the form.

Tested entering valid and invalid data in the admin UI, while watching

console output.
Valid data saved correctly, and I no longer had the decode warnings.
Invalid data resulted in a validation error in the admin UI, telling me

exactly what was wrong (according to the json module).