title: Set default value for attributes which are null while deserializing XML
body: <p>I have a xml file which I am trying to deserialize.
  I am implementing IXmlSerializable interface for Serialization and Deserialization.
  I don't see any problem with the Serialization.
  But with the deserialization I have few problems.
  1). I am using xml reader's 'ReadToFollowing' for reading elements. With this approach I have to read the values in the order of elements. If there is any mismatch in the order I am not able to read the remainig values.
  2). As per my requirement I have to provide backward compatibility in deserializing the xml. Because of this when I load some of the old version xml files(which may not contain all the elements as the latest version xml),  'ReadToFollowing' throwing exceptions.</p>
  
  <p><strong>Latest version Xml</strong></p>
  
  <pre><code>&lt;LEFTSECTION&gt;
          &lt;DATA /&gt;
          &lt;FONTNAME&gt;Arial&lt;/FONTNAME&gt;
          &lt;FONTSTYLE&gt;Regular&lt;/FONTSTYLE&gt;
          &lt;FONTSIZE&gt;10&lt;/FONTSIZE&gt;
          &lt;TEXTCOLOR&gt;-16777216&lt;/TEXTCOLOR&gt;
          &lt;STRIKEOUT&gt;0&lt;/STRIKEOUT&gt;
          &lt;UNDERLINE&gt;0&lt;/UNDERLINE&gt;
          &lt;BORDER&gt;0&lt;/BORDER&gt;
          &lt;IMAGE&gt;0&lt;/IMAGE&gt;
          &lt;IMAGENAME /&gt;
          &lt;ALIGNMENT&gt;4&lt;/ALIGNMENT&gt;
          &lt;SECTIONHEIGHT&gt;0.5454546&lt;/SECTIONHEIGHT&gt;
          &lt;SECTIONWIDTH&gt;0.33&lt;/SECTIONWIDTH&gt;
        &lt;/LEFTSECTION&gt;
  </code></pre>
  
  <p><strong>Old version Xml</strong></p>
  
  <pre><code>&lt;LEFTSECTION&gt;
          &lt;DATA&gt;asas#APP_OEM_NAME#&lt;/DATA&gt;
          &lt;FONTNAME&gt;Arial Unicode MS&lt;/FONTNAME&gt;
          &lt;FONTSTYLE&gt;Regular&lt;/FONTSTYLE&gt;
          &lt;FONTSIZE&gt;10&lt;/FONTSIZE&gt;
          &lt;TEXTCOLOR&gt;-16777216&lt;/TEXTCOLOR&gt;
          &lt;STRIKEOUT&gt;0&lt;/STRIKEOUT&gt;
          &lt;UNDERLINE&gt;0&lt;/UNDERLINE&gt;
          &lt;BORDER&gt;0&lt;/BORDER&gt;
          &lt;IMAGE&gt;0&lt;/IMAGE&gt;
          &lt;IMAGENAME&gt;
          &lt;/IMAGENAME&gt;
        &lt;/LEFTSECTION&gt;
  </code></pre>
  
  <p>Please help me on this.</p>