title: msiexec does not pass parameters to custom action
body: <p>I have a custom action inside an MSI installer that makes some changes to some configuration file.  my requirement is to run the installation in silent mode so I am using msiexec.
  Here is the command:</p>
  
  <pre><code>msiexec /i myInstaller.msi /l* out.txt myContextParameter=value1
  </code></pre>
  
  <p><code>myContextParameter</code> is never passed to the custom action so when I do
  <code>context.Parameters["myContextParameter"]</code> I get a <code>null</code> value.</p>
  
  <p>When I run my MSI in UI mode the parameter is passed correctly. I also made sure the name of the property is correctly set in the <code>CustomActionData</code>.</p>