add some simple getter/setter transaction junits tests
add setAbsolute test
fix license header
draft for AccountService
Update to SpongePowered/SpongeAPI@b0584a934fc5284edaa7ab4d44ab289d148890b7.
no non eco plugin should grab all accounts for a owner (e.g. player)
Economy is an AccountService ;)
rework economy
rename prefix to namespace