Import data from complete export JSON file

[tomzx]

As pointed out in #3, no such feature currently exist. However it would be extremely useful to be able to do so, either for debugging purposes, or for the simple fact that you could very easily generate backups through a simple backend that receives the whole JSON and stores it.

[tomzx]

Apparently done @ 3daf4d32aede3a2bdfa9b2c3c366377530f60b64.