title: When running NUnit and specifying a category, can all uncategorized tests be included too?
body: <p>We have several hundred test classes, with a few dozen of them marked with the following attributes:
      [TestFixture]
      [Explicit]
      [Category("IntegrationTests")]
  so they will only be run in our over-night automated build.  The remaining TestFixtures don't have a Category specified (and are not marked Explicit either).</p>
  
  <p>Here is the NAnt task we are running to execute our tests:</p>
  
  <pre><code>&lt;nunit2&gt;
      &lt;test&gt;
          ...
          &lt;categories&gt;
              &lt;include name="IntegrationTests" /&gt;
          &lt;/categories&gt;
          ...
      &lt;/test&gt;
  &lt;/nunit2&gt;
  </code></pre>
  
  <p>This, of course, will not execute any of the uncategorized tests.</p>
  
  <p>I'd like to be able to do something like this:</p>
  
  <pre><code>&lt;nunit2&gt;
      &lt;test&gt;
          ...
          &lt;categories&gt;
              &lt;include name="*" /&gt;
              &lt;include name="IntegrationTests" /&gt;
          &lt;/categories&gt;
          ...
      &lt;/test&gt;
  &lt;/nunit2&gt;
  </code></pre>
  
  <p>where all of the uncategorized tests will be run along with the integration tests.  Is this possible?  If so, what is the syntax?</p>
  
  <p>(Note: I'm looking for either a NAnt solution, as above, or an NUnit command-line solution.  I can certainly run NUnit twice with different options, or put Categories on all of my TestFixtures.  These are workarounds that I'm OK using if I have to, but it would be more cool to be able to specify uncategorized tests directly.)</p>