title: How to capture resizing of QTreeWidget columns
body: <p>I need a column in my QTreeWidget which's width is always x pixels.</p>
  
  <p>So i want to capture a resize of my QTreeWidget columns, to set the with back to my x on resize by user.
  But i can't find any Signal like <code>columnWidthChanged</code>.</p>
  
  <p>Is there any way to call a function/slot when a columns with is changed?
  Or is there any other solution?</p>