set height: auto on #site for print

avoids truncating printed output

IPython/html/static/base/less/page.less

@@ -89,6 +89,10 @@ body {
     display: none;
     .border-box-sizing();
     overflow: auto;
+    @media print {
+      // force auto-height on print (overrides manual resizing in live view)
+      height: auto !important;
+    }
 }
 
 /* Smaller buttons */

IPython/html/static/style/style.min.css

@@ -8466,6 +8466,11 @@ body {
   -webkit-box-sizing: border-box;
   overflow: auto;
 }
+@media print {
+  #site {
+    height: auto !important;
+  }
+}
 /* Smaller buttons */
 .ui-button .ui-button-text {
   padding: 0.2em 0.8em;