Remove obsolete ACLOCAL_AMFLAGS definition.

Fixes #138, reported by Valentin Iovene.

* Makefile.am: Here.
* THANKS: Add Valentin.

Makefile.am

@@ -61,7 +61,6 @@ DEBIAN =					\
 debian/changelog: configure.ac
 	$(top_builddir)/config.status --file debian/changelog
 
-ACLOCAL_AMFLAGS = -I m4
 EXTRA_DIST = HACKING ChangeLog.1 tools/gitlog-to-changelog	\
 	     tools/help2man tools/man2html.pl			\
 	     tools/test-driver-teamcity $(UTF8) $(DEBIAN)	\

THANKS

@@ -27,5 +27,6 @@ Rüdiger Ehlers
 Silien Hong
 Sonali Dutta
 Tomáš Babiak
+Valentin Iovene
 Vitus Lam
 Yann Thierry-Mieg