Replace skips every second occurrence

[gyorokpeter]

Recommended fix:

        boolean searchFromSelStart;
        if (context.getReplaceWith() != null) {
            searchFromSelStart = context.getSearchForward();
        } else {
            searchFromSelStart = ! context.getSearchForward();
        }
        int pos = searchFromSelStart ? textArea.getSelectionStart() : textArea.getSelectionEnd();