Provides a base panel to construct the main dashboard

This patch adds a default panel that will be used when another service
will add a new panel into the main dashboard through grains. This is the
common part between all panels of the main dashboard.

It replaces the static main dashboard that has been removed.
diff --git a/_states/grafana3_dashboard.py b/_states/grafana3_dashboard.py
index 63090ab..a4f44ca 100644
--- a/_states/grafana3_dashboard.py
+++ b/_states/grafana3_dashboard.py
@@ -128,7 +128,8 @@
     # Build out all dashboard fields
     new_dashboard = _inherited_dashboard(
         dashboard, base_dashboards_from_pillar, ret)
-    new_dashboard['title'] = name
+    if not new_dashboard.get('title'):
+        new_dashboard['title'] = name
     rows = new_dashboard.get('rows', [])
     for i, row in enumerate(rows):
         rows[i] = _inherited_row(row, base_rows_from_pillar, ret)