Pin nodes at end of mousedrag.
Allow nodes to be unpinned by hovering over and pressing 'U'.
diff --git a/web/gui/src/main/webapp/onos.css b/web/gui/src/main/webapp/onos.css
index baa00a3..3aade2c 100644
--- a/web/gui/src/main/webapp/onos.css
+++ b/web/gui/src/main/webapp/onos.css
@@ -132,7 +132,8 @@
 }
 
 
-svg .node.selected rect {
+svg .node.selected rect,
+svg .node.selected circle {
     filter: url(#blue-glow);
 }