split out handler implementation from interface

Split out the handler object definition from the interface and drop the
default parameters.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: Ie8c9dbf7881bbe6b5af3596a60430e3b3d573762
diff --git a/handler.cpp b/handler.cpp
index 341e195..4605e2f 100644
--- a/handler.cpp
+++ b/handler.cpp
@@ -17,6 +17,7 @@
 #include "handler.hpp"
 
 #include "errors.hpp"
+#include "handler_impl.hpp"
 #include "util.hpp"
 
 #include <ipmid/api.h>
@@ -276,7 +277,5 @@
 const std::string defaultConfigFile =
     "/usr/share/ipmi-entity-association/entity_association_map.json";
 
-Handler handlerImpl;
-
 } // namespace ipmi
 } // namespace google