How to store the currency configuration in the DB

[rabol]

Hi

in #71

there is a comment that indicate that you can store the currency configuration in a db instead of the config file.

I tried to look for the boot() method that load the currency configuration, but I could not find it.

I would like to have the currency information in the db to avoid loading a lot of currencies that I don't need, in most cases one would max need 3 (for triangulation)

What would be the best way to get it working ?