(ui) upgrade nvd3 to 1.8.2

(cherry picked from commit 7ac4ff52)
(cherry picked from commit 331d5a8f)

src/opnsense/www/css/nv.d3.css

-/* nvd3 version 1.8.1 (https://github.com/novus/nvd3) 2015-06-15 */
+/* nvd3 version 1.8.2 (https://github.com/novus/nvd3) 2016-01-24 */
 .nvd3 .nv-axis {
     pointer-events:none;
     opacity: 1;
@@ -408,9 +408,12 @@ svg.nvd3-svg {
     stroke-opacity: 1;
 }
 
-.nvd3.nv-pie .hover path {
+.nvd3.nv-pie path {
     fill-opacity: .7;
 }
+.nvd3.nv-pie .hover path {
+    fill-opacity: 1;
+}
 .nvd3.nv-pie .nv-label {
     pointer-events: none;
 }
@@ -592,7 +595,10 @@ svg.nvd3-svg {
 }
 
 .nvtooltip table td.key {
-    font-weight:normal;
+    font-weight: normal;
+}
+.nvtooltip table td.key.total {
+    font-weight: bold;
 }
 .nvtooltip table td.value {
     text-align: right;