title: How can I center align text in jqgrid header group
body: <p>I am using <a href="http://www.trirand.com/blog/?p=857" rel="nofollow noreferrer">the new header grouping feature of jqgrid 4.2</a> which works great except that it left aligns all of the text in the header groups.</p>
  
  <p>How can align the header group text to be center in the cell?</p>
  
  <p>Here is a screenshot to show you how it seems to be working by default:  (I want "Books" to be center aligned")</p>
  
  <p>NOTE: the regular column headers ARE center aligned.</p>
  
  <p><img src="https://i.stack.imgur.com/xEcD0.png" alt="enter image description here"></p>