title: Can't install JUnit into Netbeans 8 offline
body: <p>I've downloaded the 2 NBM's for JUnit.  In Netbeans 8 I'm using the Tools->Plugins->Downloaded window and have added the pertinent NMBs.  They are both check-marked and when I press "Install" Netbeans then pops open a dialog that says (approximately) "Installer will download, verify, then install the selected modules".  It then does attempt to use the Internet to download - and fails.  This machine has no access to the Internet (hence the offline approach).</p>
  
  <p>Have I not downloaded the proper NBMs (they were ZIP files and I renamed them to NBM - read that was the thing to do)?  Is there some other piece that I'm missing?</p>