title: Quartz.Net with XmlPlugin, use Misfire with overwrite-existing-data
body: <p>I'm using Quartz.Net (v 3.0.1) for the first time, with the XML Plugin to schedule the jobs and triggers from a XML file. </p>
  
  <p>I need in particular two features:</p>
  
  <ul>
  <li>To use the misfire policy, for example <code>FireOnceNow</code> for a certain job scheduled with a cron trigger that had a misfire </li>
  <li>To load at run time other jobs and trigger (modifying the XML)</li>
  </ul>
  
  <p>Right now I'm stuck with this problem:</p>
  
  <p>I found online various topic (like this one: <a href="https://stackoverflow.com/questions/13085934/how-to-use-cron-misfire-instruction-fireoncenow-with-adojobstore-in-quartz-net-2">How to use cron misfire-instruction FireOnceNow with AdoJobStore in Quartz.NET 2.0?</a>) where is explained that <code>&lt;overwrite-existing-data&gt;</code> needs to be at false to use the misfire instructions.
  And effectively with this setting the job is re-fired if there was a misfire.</p>
  
  <p>The problem is that in this way I can't insert other jobs and triggers in the XML file:</p>
  
  <pre><code>[12:43:25] [Error] Could not schedule jobs and triggers from file
      ~/quartz_jobs.xml: Unable to store Job: 'JobGroup1.TestJob1', 
      because one already exists with this identification.
  </code></pre>
  
  <p>I don't want every time to delete from XML all the jobs and trigger to add the new one. (I prefer to have in the XML the trace off all my scheduled jobs and triggers)</p>
  
  <p>I'd like to understand what it has to do the <code>&lt;overwrite-existing-data&gt;</code> with the misfire policy in each job.</p>