implement journal#connect_to_invoice
change views/invoices/show
change journals/update_all when params[:belong_journal_ids].blank
add scope invoice#unfinished_payment
change journals/show layouts
add invoice.payment form
hide edit journal and cost buttons when invoice.payment == true
change journal edit condition in each views
add validation of journal#update when journal.invoice.payment == true
add validation of cost#update when cost.invoice.payment == true
implement invoice.update_summary after_save costs
add invoice.update after journals/update_all
set validates of journal
set validates of bank
set validates of company