Now is supported LATIN1, LATIN2, WIN1250. For other character sets I
haven't good resources. Add new encoding is easy...
If encoding is not supported returns ERROR.
Note --- not exists total corect conversion to ASCII, this function try
convert chars those is _probably_ interpret-able in ASCII for
others use ' '. But for example for all Czech characters it is
sufficient ... hmm Chinese / JAP and other complicated langs
have
bad luck here :-(