Fix regeneration of ./configure from configure.ac when using make

To use an m4 macro library you need three things:

* configure.ac mentions it (OK)
* autogen.sh mentions it (OK)
* Makefile.am mentions it (fixed by this patch)

Omission of the third part means that when you change configure.ac and run
make, ./configure is rebuilt without using the m4 directory, so autoconf
doesn't load python.m4 and the rebuild fails.

Makefile.am

@@ -1,3 +1,5 @@
+ACLOCAL_AMFLAGS = -I m4
+
 SUBDIRS = bin data lib po shell sugar services
 
 bin_SCRIPTS = 			\