Fix dbus-c++ to compile examples in a cross compilation environment

examples/echo/Makefile.am

Index: examples/echo/Makefile.am
diff --git a/examples/echo/Makefile.am b/examples/echo/Makefile.am
index 63fe2eb1f0f31b0cae3218e5fdbb3471072ae649..76bddad9bcf951a339fed3627dcc0180b553d2ec 100644
--- a/examples/echo/Makefile.am
+++ b/examples/echo/Makefile.am
@@ -1,5 +1,11 @@
 EXTRA_DIST = README echo-introspect.xml
 
+if CROSS_COMPILING
+dbusxx_xml2cpp = dbusxx-xml2cpp
+else
+dbusxx_xml2cpp = $(top_builddir)/tools/dbusxx-xml2cpp
+endif
+
 AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include 
 
 noinst_PROGRAMS = echo-server
@@ -8,7 +14,7 @@ echo_server_SOURCES = echo-server-glue.h echo-server.h echo-server.cpp
 echo_server_LDADD = $(top_builddir)/src/libdbus-c++-1.la
 
 echo-server-glue.h: echo-introspect.xml
-	$(top_builddir)/tools/dbusxx-xml2cpp $^ --adaptor=$@
+	$(dbusxx_xml2cpp) $^ --adaptor=$@
 
 noinst_PROGRAMS += echo-client-mt
 
@@ -17,7 +23,7 @@ echo_client_mt_LDADD = $(top_builddir)/src/libdbus-c++-1.la @PTHREAD_LIBS@
 echo_client_mt_CXXFLAGS = @PTHREAD_CFLAGS@
 
 echo-client-glue.h: echo-introspect.xml
-	$(top_builddir)/tools/dbusxx-xml2cpp $^ --proxy=$@
+	$(dbusxx_xml2cpp) $^ --proxy=$@
 
 BUILT_SOURCES = echo-server-glue.h echo-client-glue.h
 CLEANFILES = $(BUILT_SOURCES)