constructed it it won't be deleted again by 'make clean'. The effect
is that not only does this work (as r9288 arranged),
./configure; make plink
but these work too:
./configure; make; make clean; make plink
./configure; make; make distclean; ./configure; make plink
[originally from svn r9290]
[r9288 ==
a4424bfd85a44a7aed5e6d5f85daaeb86c0f24e5]
!cflags am version $(VER) -DINCLUDE_EMPTY_H `if test -z "$(VER)" && (cd $(srcdir)/..; md5sum -c manifest >/dev/null 2>&1); then cat $(srcdir)/../version.def; else echo "$(VER)"; fi`
!begin am
BUILT_SOURCES = empty.h
-CLEANFILES = empty.h
empty.h: $(allsources)
echo '/* Empty file touched by automake makefile to force rebuild of version.o */' >$@