title: QProcess started from a QMainWindow freezes window
body: <p>I have a simple <code>QMainWindow</code> in which user can set some parameters.
  I have three buttons which, when clicked, create a new <code>QProcess</code> displaying a <code>QMainWindow</code>. For example, main window's button <code>A</code> starts QProcess <code>A</code>, main window's button <code>B</code> starts process <code>B</code>, etc. 
  I'd like to be able to interact with the main window, because now when I click the button the <code>QProcess</code> starts correctly, displaying another window etc, but the original main window stays <em>frozen</em> until the <code>QProcess</code> ends.</p>
  
  <p>Is there a way to maintain the main window responsive, in order to be possible to interact with it <strong>WHILE</strong> the QProcess/QProcesses runs/run?</p>
  
  <p><strong>EDIT:</strong> here's how I start processes:</p>
  
  <pre><code>QProcess process;
  process.execute("../../RRTStar/RRTStar", QStringList() &lt;&lt; "--file" &lt;&lt; "../../settings.conf");
  </code></pre>
  
  <p>where <code>RRTStar</code> is the name of the executable and <code>--file ../../settings.conf</code> are the command line parameters. Note that RRTStar is composed of a MainWindow and runs heavy computation using threads.</p>