parse_params interface

Parses parameters/attribute data.
    When user  gets parameter/property of the camera by get_properties/get_params function ,
The rc_ipcam library by GET_PROPERTIES_RESULT and the GET_PARAMS_RESULT event notification user,
The lParam parameter for the GET_RESULT_PARAM data type, 
the member variable content, content_len are the parameter/property data which return from camera .(please refer to the specific GET_RESULT_PARAM type description).

    The user can call this function to parse the parameters/properties data. 
Because the parameters/property data maybe include a more than one parameter/ property,
the user needs to loop calls the function to achieve the parsing all parameter/property.

For example:

    void CTest2Dlg::on_get_properties_result(WPARAM wParam, LPARAM lParam)
    {
        GET_RESULT_PARAM * param = (GET_RESULT_PARAM *)lParam;
        char * content = param->content;
        unsigned int content_len = param->content_len;
        char * name, * value;
        CString str;
        while (parse_params(&content, &content_len, &name, &value))
        {
            str.Format("%s=%s",name,value);
            m_properties_list.InsertString(-1, str);
        }
        free_get_result_param(param);
     }

    Note, this function returns *name and *value and the new rc_ipcam memory allocation is not,
But directly to the memory of content. Therefore, if the user releases the content,
Then *name and *value are illegal pointer, continue to access will be abnormal.