PY: richer ORAL.
PY: updated Structures, include cat links.
PY: somewhat save entries.
PY: modify and remove accounts.
PY: added AccountsManager.
PY: migrate to AccountsManager.
PY: added basic OperationsTab UI.
PY: added OperationPropsDialog.
PY: support initializing References<> from PKey<>.
PY: support QDateTime.
PY: added Core.
PY: way better structures hierarchy.
PY: added OperationsManager.
PY: support setting account currency.
PY: adapt ReceiptEntry::Date_ as well.
PY: more Entries API.
PY: AccountsManager::GetAccount().
PY: added EntriesModel.
PY: OperationsManager::AddEntry().
PY: support adding operations.