rem: supprime_operation ( gsb_account_get_current_transaction (compte_courant) );
add: gsb_transactions_list_delete_transaction ( gsb_account_get_current_transaction (gsb_account_get_current_account ()) );
context: void remove_transaction (){    if (! assert_selected_transaction()) return;    supprime_operation ( gsb_account_get_current_transaction (compte_courant) );    gtk_notebook_set_page ( GTK_NOTEBOOK ( notebook_general ), 1 );}