Use open-source accounting (GnuCash) for future expenditures

Seeing the total expenditures for the Miami Basel event (137 ETH), it is apparent that there is a disparity between the Doodles that don't mind the expenses and Doodles that DO mind the expenses incurred.

The main reasons for this disparity are :

1. That it is hard to quantify the value that a 137 ETH event has bought for the community

2. Even if the event has bought a lot of value for the community, there might be more ways to practice PRUDENT SPENDING for future events

3. The "reimburse snapshot" came in retroactively, instead of proactively, making it quite a surprise for the rest of the community