title: BindingSource.Find throws NotSupportedException (DataSource is BindingList<T>)
body: <p>I've got a <code>BindingSource</code> with a <code>BindingList&lt;Foo&gt;</code> attached as the data source. I'd like to work with the <code>BindingSource</code>'s <a href="http://msdn.microsoft.com/en-us/library/ms158165.aspx" rel="noreferrer"><code>Find</code> method</a> to look up an element. However, a <code>NotSupportedException</code> is thrown when I do the following, even though my data source does implement <code>IBindingList</code> (and no such exception is documented in MSDN):</p>
  
  <pre><code>int pos = bindingSource1.Find("Bar", 5);
  </code></pre>
  
  <p>I attached a short example below (a <code>ListBox</code>, a <code>Button</code> and a <code>BindingSource</code>). Could anybody help me getting the <code>Find</code> invocation working?</p>
  
  <pre><code>public partial class Form1 : Form
  {
      public Form1() { InitializeComponent(); }
  
      private void Form1_Load(object sender, EventArgs e)
      {
          var src = new BindingList&lt;Foo&gt;();
          for(int i = 0; i &lt; 10; i++)
          {
              src.Add(new Foo(i));
          }
  
          bindingSource1.DataSource = src;
      }
  
      private void button1_Click(object sender, EventArgs e)
      {
          int pos = bindingSource1.Find("Bar", 5);
      }
  }
  
  public sealed class Foo
  {
      public Foo(int bar)
      {
          this.Bar = bar;
      }
  
      public int Bar { get; private set; }
  
      public override string ToString()
      {
          return this.Bar.ToString();
      }
  }
  </code></pre>