D: Fix out-of-source build for examples.

Examples/d/callback/Makefile

@@ -1,27 +1 @@
-ifeq (2,$(D_VERSION))
-  WORKING_DIR = d2/
-else
-  WORKING_DIR = d1/
-endif
-
-TOP           = ../../..
-SWIG          = $(TOP)/../preinst-swig
-EXTRA_CFLAGS  = -I../ ../example.cxx example_wrap.cxx
-EXTRA_LDFLAGS = example.o example_wrap.o
-TARGET        = example_wrap
-SWIGOPT       =
-DSRCS         = *.d
-DFLAGS        = -ofrunme
-
-check: build
-	cd $(WORKING_DIR); \
-	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' d_run
-
-build:
-	cd $(WORKING_DIR); \
-	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' EXTRA_CFLAGS='$(EXTRA_CFLAGS)' EXTRA_LDFLAGS='$(EXTRA_LDFLAGS)' SWIG='$(SWIG)' SWIGOPT='$(SWIGOPT) -outcurrentdir ../example.i' TARGET='$(TARGET)' d_cpp; \
-	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' DSRCS='$(DSRCS)' DFLAGS='$(DFLAGS)' d_compile
-
-clean:
-	cd $(WORKING_DIR); \
-	$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' d_clean
+include ../example.mk