Add ledger page for accounts with chronological change to wallet and running balance

[GeorgLink]

I envision a table with a chronological account of events on the user's account. Similar to a bank statement. Important for trust could be a running balance.

Relates to #67 to show how the account should be effected by the J J Demo.

DateTime	Event	Outflow	Inflow	Balance
2018-02-03 12:00:00	Starting Balance	1000
2018-02-03 18:35:01	Escrow for Buy Offer # 273	10		990
2018-02-03 18:37:58	Payout of Contract # 23		100	1090

[andyl]

Moved to bugmark/test_bench#100