Improve dashboard, add numberic statistic fields

salt_observer/assets/less/_init.less

@@ -5,6 +5,7 @@
 @import (inline) "../../../node_modules/vis/dist/vis.css";
 
 /* Now import own styles */
+@import "variables.less";
 @import "base.less";
 @import "login.less";
 @import "sidebar.less";