Disable transaction id support by default

Allow the transaction id support to be enabled via
configure options.
In the code, ifdef the code based if transaction support
is desired.

Change-Id: I98695268397f437b6fe14621f820fbcaecb45b7a
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/Makefile.am b/Makefile.am
index 552dc69..175355c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -22,12 +22,18 @@
 	sdbusplus/utility/type_traits.hpp \
 	sdbusplus/vtable.hpp
 
-LIBSDBUSPLUS_FILES = \
+LIBSDBUSPLUS_FILES =
+
+if WANT_TRANSACTION
+LIBSDBUPLUS_FILES_TRANSACTION = \
 	sdbusplus/server/transaction.cpp
+endif
 
 libsdbusplusdir = ${libdir}
 libsdbusplus_LTLIBRARIES = libsdbusplus.la
-libsdbusplus_la_SOURCES = $(LIBSDBUSPLUS_FILES)
+libsdbusplus_la_SOURCES = \
+	$(LIBSDBUSPLUS_FILES) \
+	$(LIBSDBUPLUS_FILES_TRANSACTION)
 libsdbusplus_la_LDFLAGS = $(SYSTEMD_LIBS) -version-info 1:0:0 -shared
 libsdbusplus_la_CXXFLAGS = $(SYSTEMD_CFLAGS)