Fix all references to config.h

config.h is created in $(top_buildir)/config.h.
Let's make sure all CPPFLAGS add correct -Ipath includes,
and that all code includes the correct file.

Change-Id: Ie9ea38bb009bc715b01cde4d66d181f7bec2e7bd
diff --git a/src/coding/Makefile.am b/src/coding/Makefile.am
index d856918..42b16e8 100644
--- a/src/coding/Makefile.am
+++ b/src/coding/Makefile.am
@@ -5,7 +5,9 @@
 
 AM_CPPFLAGS = \
 	-I"$(top_srcdir)/include" \
-	-I"$(top_builddir)/include"
+	-I"$(top_builddir)/include" \
+	-I"$(top_builddir)" \
+	$(NULL)
 AM_CFLAGS = -Wall $(TALLOC_CFLAGS)
 
 if ENABLE_PSEUDOTALLOC