Create a /summaries call with a merge of data with our current active balances

[elboletaire]

Excepting these two cases:

• Currency BTC (it's our base coin, we shall ignore it)
• Currencies with zero balance. In a near future would be nice to also have a /summaries/history with not only the currencies with zero balance, but also any other we've traded over time.

We should loop over all our /account/balances > 0 and then do a call to /account/getorderhistory for each currency. There we need to:

• Take all sell orders and sum them.
• Take all buy orders and rest it to the result of the sell sum

So the /summaries for now should return an array (or maybe better, an object with the currencies as key) with a total key for each object with the result of the above operation..

In a near future this call will also have a profit key with a % of our profit or benefit (negative or positive, but a percentage after all).