解决FastJson 1.2.39的bug

1、日期转换默认格式覆盖注解格式的bug；

com.alibaba.fastjson.serializer.JSONSerializer#writeWithFormat

修改后的代码：

public final void writeWithFormat(Object object, String format) {
    if (object instanceof Date) {
        DateFormat dateFormat = this.getDateFormat();
        if(format!=null){
            dateFormat = new SimpleDateFormat(format, locale);
            dateFormat.setTimeZone(timeZone);
        }
        String text = dateFormat.format((Date) object);
        out.writeString(text);
        return;
    }
    write(object);
}

2、解决转JSON时候Bean字段默认被排序的毛病：

com.alibaba.fastjson.serializer.SerializeWriter#computeFeatures

修改的代码：

    protected void computeFeatures() {
        quoteFieldNames = (this.features & SerializerFeature.QuoteFieldNames.mask) != 0;
        useSingleQuotes = (this.features & SerializerFeature.UseSingleQuotes.mask) != 0;
//        sortField = (this.features & SerializerFeature.sortField.mask) != 0;
        sortField = false;
        disableCircularReferenceDetect = (this.features & SerializerFeature.disableCircularReferenceDetect.mask) != 0;
        beanToArray = (this.features & SerializerFeature.BeanToArray.mask) != 0;
        writeNonStringValueAsstring = (this.features & SerializerFeature.WriteNonStringValueAsstring.mask) != 0;
        notWriteDefaultValue = (this.features & SerializerFeature.NotWriteDefaultValue.mask) != 0;
        writeEnumUsingName = (this.features & SerializerFeature.WriteEnumUsingName.mask) != 0;
        writeEnumUsingToString = (this.features & SerializerFeature.WriteEnumUsingToString.mask) != 0;

        writeDirect = quoteFieldNames //
                      && (this.features & nonDirectFeautres) == 0 //
                      && (beanToArray || writeEnumUsingName)
                      ;

        keySeperator = useSingleQuotes ? '\'' : '"';
    }