Don't use the checkable header view for now

The ctkDICOMModel interface doesn't seem to have a good way
to store the StudyUID for later use in the retreival step and doesn't
have a handy way to get a checkbox status to indicate only the studies
to be downloaded.  We'll need to work on that, but for now let's just
assume that the user will be able to use all the other query tools
to be able to narrow down the specific studies to be retrieved (i.e.
by date, name, modality, etc).  In practice this seems to be
pretty workable.

Libs/DICOM/Widgets/ctkDICOMQueryRetrieveWidget.cpp

@@ -103,8 +103,11 @@ void ctkDICOMQueryRetrieveWidgetPrivate::init()
   QObject::connect(this->CancelButton, SIGNAL(clicked()), q, SLOT(cancel()));
 
   this->results->setModel(&this->Model);
+  // TODO: use the checkable headerview when it becomes possible
+  // to select individual studies.  For now, assume that the 
+  // user will use the query terms to narrow down the transfer
+  /*
   this->Model.setHeaderData(0, Qt::Horizontal, Qt::Unchecked, Qt::CheckStateRole);
-
   QHeaderView* previousHeaderView = this->results->header();
   ctkCheckableHeaderView* headerView =
     new ctkCheckableHeaderView(Qt::Horizontal, this->results);
@@ -115,6 +118,7 @@ void ctkDICOMQueryRetrieveWidgetPrivate::init()
   this->results->setHeader(headerView);
   // headerView is hidden because it was created with a visisble parent widget 
   headerView->setHidden(false);
+  */
 }
 
 //----------------------------------------------------------------------------
@@ -248,6 +252,9 @@ void ctkDICOMQueryRetrieveWidget::retrieve()
 
   foreach( QString studyUID, d->QueriesByStudyUID.keys() )
     {
+    // TODO: check the model item to see if it is checked
+    // for now, assume all studies will be retreived
+
     logger.debug("About to retrieve " + studyUID + " from " + d->QueriesByStudyUID[studyUID]->host());
     ctkDICOMQuery *query = d->QueriesByStudyUID[studyUID];
     ctkDICOMRetrieve *retrieve = new ctkDICOMRetrieve;