Removed national credit transfers
Review Request #130135 - Created May 18, 2017 and submitted
They are not supported by the banks anymore. So they can be removed. Unfortunately they contained the only example for a task converter. Due to the removed plugin the CMakeLists.txt for sepa could be simplified. Cherry-picked from d514e650
Successfully builds again with the patch (there was a moc error after upgrade to boost-1.63).