Initial support for event callbacks

Add parser support for template rendering of events.
Also defines the EventBase and Event classes.
EventBase is parent of Event.

Change-Id: I6b07b415acf510a8437529095bd489c0af73ddf5
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/src/Makefile.am b/src/Makefile.am
index c20b9dd..cf91619 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -32,7 +32,8 @@
 	templates/elog.mako.cpp \
 	templates/errors.mako.hpp \
 	templates/method.mako.cpp \
-	templates/resolve_errors.mako.cpp
+	templates/resolve_errors.mako.cpp \
+	templates/event.mako.cpp
 
 generated.hpp: $(PDMGEN) $(YAML_PATH) $(TEMPLATES)
 	$(AM_V_GEN)$(PYTHON) ${PDMGEN} \