Signing on the way. There is a bug becuse of ucoin API using keyword "self", and it's conflicting with python self keyword.

We can export and import accounts

Configuring account reworking
Some bugs fixed

Account now has Wallets and Communities
Wallets are now managing the network side of ucoin
A community doesnt depend anymore on a wallet
A wallet knows what community it is part of thanks to currency name

Refactoring
Debugging

Configuring account : changing its name and the communities

Sauvegarde de fichier, utilisation de "factory" pour créer des models a partir de rien ou a partir de json.

Listing des communautés, démarrage du coeur de l'application, avec de le la sauvegarde au format JSON