automake: replace INCLUDES by AM_CPPFLAGS

INCLUDES are now deprecated and throw warnings when using automake 1.13.
We now also differentiate AM_CPPFLAGS and AM_CFLAGS, where includes and
defines are passed to AM_CPPFLAGS only.

src/_copyright/Makefile.am

@@ -1,7 +1,7 @@
 ipsec_PROGRAMS = _copyright
 _copyright_SOURCES = _copyright.c
 
-INCLUDES = \
--I$(top_srcdir)/src/libstrongswan
+AM_CPPFLAGS = \
+	-I$(top_srcdir)/src/libstrongswan
 
 _copyright_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la