flowplace

Add a per user currency accounts interface, that allows seeing and using currencies according to the currency types.

In order to be able to play we need to be able to transfer one currency from one account to another. The transaction capacity is one of the top functionnalities we need to start playing.

There are different forms of transactions:

- created: one account "creates" a currency in another account. Examples: flowers, hearts (for reputation), and also WE's when TheTransitioner is issuing more monetary mass.
- transfered: when an account goes down by X and the other goes up by X (fiat money transfer or mutual credit)

We want to be aware that a transaction to a new account can only be made when the account has joined the group in which the currency is used.