change verifymessagepage behaviour to match RPC-call "verifymessage" (input address, signature and message) / display messages in status label (remove message boxes) / resize window to make signature fully readable / change signature font to BC-address font (like in messagepage) / remove checkAddress() and place code directly in on_verifyMessage_clicked() / add visual feedback to LineEdits / remove AddressTableModel references, as they are now unused / add addr.GetKeyID(keyID) check