#3248 mread-synerr produces error messages that don't end in a newline

[Gunter Königsmann]

errcatch(parse_string("x+"))

sends an error message to wxMaxima that doesn't end in a newline => I've changed wxMaxima to handle error messages even if they don't end in a newline.

If I don't interpret things wrong I assume, though, that the error message was supposed to end in a newline and that the cause for it not doing this is that mread-synerr (which is defined in nparse.lisp) doesn't add a newline to its output even if it seems only to be called with arguments that don't end with a newline themselves.