Fix compilation if libarchive headers are not in standard location

With commit 097d5a478b, including alpm.h also drags in archive.h.
Ensure the tools we build that depend on ALPM also include the necessary
flags to find libarchive headers if they are not installed in a standard
location.

[Dan: Add commit message]
Signed-off-by: Dan McGee <dan@archlinux.org>
Signed-off-by: Allan McRae <allan@archlinux.org>

Signed-off-by: Allan McRae <allan@archlinux.org>

src/pacman/Makefile.am

@@ -19,7 +19,8 @@ AM_CPPFLAGS = \
 	-DCACHEDIR=\"$(cachedir)\" \
 	-DLOGFILE=\"$(logfile)\"
 
-AM_CFLAGS = -pedantic -D_GNU_SOURCE $(WARNING_CFLAGS)
+AM_CFLAGS = -pedantic -D_GNU_SOURCE $(WARNING_CFLAGS) \
+	$(LIBARCHIVE_CFLAGS)
 
 if USE_GIT_VERSION
 GIT_VERSION := $(shell sh -c 'git describe --abbrev=4 --dirty | sed s/^v//')

src/util/Makefile.am

@@ -15,7 +15,8 @@ AM_CPPFLAGS = \
 	-DGPGDIR=\"$(gpgdir)\" \
 	-DCACHEDIR=\"$(cachedir)\"
 
-AM_CFLAGS = -pedantic -D_GNU_SOURCE $(WARNING_CFLAGS)
+AM_CFLAGS = -pedantic -D_GNU_SOURCE $(WARNING_CFLAGS) \
+	$(LIBARCHIVE_CFLAGS)
 
 cleanupdelta_SOURCES = cleanupdelta.c
 cleanupdelta_LDADD = $(top_builddir)/lib/libalpm/.libs/libalpm.la