Add support for callbacks

Callbacks are the response in the PDM 'trigger->response' model.
Add general support for implementing callbacks and implement
a log to systemd journal using that framework.

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Change-Id: I8bead5368ee5472a02b47e8bba9e9df3a1f346bc
diff --git a/src/Makefile.am b/src/Makefile.am
index 3b4d9cf..f223713 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -7,6 +7,7 @@
 
 phosphor_dbus_monitor_SOURCES = \
 	functor.cpp \
+	journal.cpp \
 	main.cpp \
 	monitor.cpp \
 	propertywatch.cpp
@@ -21,7 +22,8 @@
 CLEANFILES = generated.hpp
 
 TEMPLATES = \
-	templates/generated.mako.hpp
+	templates/generated.mako.hpp \
+	templates/journal.mako.cpp
 
 generated.hpp: $(PDMGEN) $(YAML_PATH) $(TEMPLATES)
 	$(AM_V_GEN)$(PYTHON) ${PDMGEN} \