Parsing ends if field includes nullchar about chcsvparser

[turkenh]

I parsed successfully with the following workaround:

++ - (void)_parseFieldNullChar {
++    if ([self _peekCharacter] == NULLCHAR) {
++        [self _advance];
++    }
++}

- (BOOL)_parseField {
    if (_cancelled) { return NO; }

    BOOL parsedField = NO;
    [self _beginField];

    // consume leading whitespace
    [self _parseFieldWhitespace];

    // consume leading nullchar
++  [self _parseFieldNullChar];

But I am not sure about its side effects.