In my earlier post I managed to solve the problem. But, on forms where I tried to use Primefaces' commandButton instead of "regular" commandButton, I encountered a new problem. Somehow, Primefaces ignore charset settings (even when custom Filter is included in chain) and wrong charset text is passed to managed bean's actionListener method. If ajax attribute is set to false, everything works fine, problem only occurs when ajax request is sent.
Does anybody have an idea how to solve this problem?