title: Use extension and normal attributes together in xsd
body: <p>I'm trying to make mapping and i need to use:</p>
  
  <ul>
  <li>Config.xxx.yyy.KeyPair[z].normalAttribute</li>
  <li>Config.xxx.yyy.KeyPair[z]@extendAttribute</li>
  </ul>
  
  <p><em>KeyPair could be used from 0 to x times</em></p>
  
  <ul>
  <li>Extra attribs: KeyId, KeyType, ValidTo, Active </li>
  <li>Normal attribs: PrivateKey, PublicKey</li>
  </ul>
  
  <p>But error is thrown when i'm trying to load xsd file in C#:</p>
  
  <pre><code>System.Xml.Schema.XmlSchemaException: The type attribute cannot be present with either simpleType or complexType.
  </code></pre>
  
  <p>Here is shown shorten version how i made it, but it doesn't work at all:</p>
  
  <pre><code>&lt;xs:element name="Config"&gt;
    &lt;xs:complexType&gt;
      &lt;xs:all&gt;
        &lt;xs:element name="xxx"&gt;
          &lt;xs:complexType&gt;
            &lt;xs:all&gt;
              &lt;xs:element name="EncryptionKeys" type="yyy"/&gt;
            &lt;/xs:all&gt;
          &lt;/xs:complexType&gt;
        &lt;/xs:element&gt;
      &lt;/xs:all&gt;
    &lt;/xs:complexType&gt;
  &lt;/xs:element&gt;
  
  &lt;xs:element name="yyy"&gt;
    &lt;xs:complexType&gt;
      &lt;xs:sequence&gt;
        &lt;xs:element name="KeyPair" type="KeyPairExtraTypes" maxOccurs="unbounded" minOccurs="0"&gt;
          &lt;xs:complexType&gt;
            &lt;xs:attributeGroup ref="KeyPairAttributes"/&gt;
            &lt;xs:attributeGroup ref="KeyPairExtraTypes"/&gt;
          &lt;/xs:complexType&gt;
        &lt;/xs:element&gt;
      &lt;/xs:sequence&gt;
    &lt;/xs:complexType&gt;
  &lt;/xs:element&gt;
  
  &lt;xs:attributeGroup name="KeyPairAttributes"&gt;
    &lt;xs:attribute name="PrivateKey" type="xs:string"/&gt;
    &lt;xs:attribute name="PublicKey" type="xs:string"/&gt;
  &lt;/xs:attributeGroup&gt;
  
  &lt;xs:complexType name="KeyPairExtraTypes"&gt;
    &lt;xs:simpleContent&gt;
      &lt;xs:extension base="xs:string"&gt;
        &lt;xs:attribute type="xs:string" name="KeyId"/&gt;
        &lt;xs:attribute type="xs:string" name="KeyType" use="required"/&gt;
        &lt;xs:attribute type="xs:string" name="ValidTo" use="optional"/&gt;
        &lt;xs:attribute type="xs:bool" name="Active" use="required"/&gt;
      &lt;/xs:extension&gt;
    &lt;/xs:simpleContent&gt;
  &lt;/xs:complexType&gt;
  </code></pre>