Add property watches

Property watches cache DBus property values given an externally
supplied index of property names and paths, in an externally
supplied storage location.

Change-Id: I155081da88c3ab0e4f6a13b012fc9719203b1888
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/src/Makefile.am b/src/Makefile.am
index 0dfe63b..3b4d9cf 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -8,7 +8,8 @@
 phosphor_dbus_monitor_SOURCES = \
 	functor.cpp \
 	main.cpp \
-	monitor.cpp
+	monitor.cpp \
+	propertywatch.cpp
 phosphor_dbus_monitor_LDADD = \
 	$(SDBUSPLUS_LIBS) \
 	$(PHOSPHOR_LOGGING_LIBS)