title: YamlDotNet deserialization throwing exception when YAML document has a field not in type
body: <p>Does YamlDotNet support deserializing a document where there are fields in the document that do not map to a field in the resulting object? For example:</p>
  
  <p>Given a type:</p>
  
  <pre><code>public class Foo {
      public string AField { get; set; }
  }
  </code></pre>
  
  <p>If I use YamlDotNet's Deserialize on the following document it generates an exception:</p>
  
  <pre><code>Foo:
    AField: This is a test
    NotFoundField: This field is not supported yet
  </code></pre>
  
  <p>Looking at the YAML spec it should be allowable that the non-matching field should be ignored. Looking at the YamlDotNet code, it looks like it is assumed that the all fields in the document will map into the resulting object.</p>
  
  <p>Is there an existing way to make the parsing "permissive" or am I going to need to modify YamDotNet to allow this?</p>