[hitori] build: Add ACLOCAL_AMFLAGS to Makefile.am

[Philip Withnall <pwithnall src gnome org>]

commit ba45cd7868866bf38d1759b83fe32e08ccb10de1
Author: Philip Withnall <philip withnall collabora co uk>
Date:   Wed Mar 11 12:24:07 2015 +0000

    build: Add ACLOCAL_AMFLAGS to Makefile.am
    
    So that aclocal knows where local macros are.
    
    https://wiki.gnome.org/Projects/GnomeCommon/Migration

 Makefile.am |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index f0ba16b..588b3b2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,5 +1,7 @@
 SUBDIRS = help po
 
+ACLOCAL_AMFLAGS = --install -I m4 ${ACLOCAL_FLAGS}
+
 # Executable
 bin_PROGRAMS = src/hitori