Restructure Database #82
Description
We should restructure the database to fit the needs for issues #68, #67 and #65 in the following way:
One table with transactions, containing column [id, from, to, amount, reasonID, state] and another table, that contains the "events" or "reasons" for an transaction (e.G. debts or an event). By this we can make more payday rounds and reduce the columns in the transaction-table to one single entry for each user-pair (and set the other transactions to some "included in payday"-state).