ONOS-4359: continued work on theming UI
- topo view: fixed device/host badge rendering
- added "mojoColor" mock server scenario

Change-Id: I5d2da657580503abd8015875d45d2e715d44033a
(cherry picked from commit 44c440f)
diff --git a/web/gui/src/main/webapp/app/view/topo/topoModel.js b/web/gui/src/main/webapp/app/view/topo/topoModel.js
index d104449..7679fe1 100644
--- a/web/gui/src/main/webapp/app/view/topo/topoModel.js
+++ b/web/gui/src/main/webapp/app/view/topo/topoModel.js
@@ -69,7 +69,7 @@
         }
 
         // else if we have [x,y] cached in meta data, use that...
-        if (x && y) {
+        if (x !== undefined && y !== undefined) {
             node.fixed = true;
             node.px = node.x = x;
             node.py = node.y = y;