Resolve lintian errors for debian package

Reported by Ivo De Decker

debian/changelog

@@ -2,7 +2,7 @@ libmodbus (2.9.2-1) maverick; urgency=low
 
   * New upstream release
 	
- -- Stéphane Raimbault <stephane.raimbault@gmail.com>  Mon, Oct 4 2010 13:21:52 +0200
+ -- Stéphane Raimbault <stephane.raimbault@gmail.com>  Mon, 4 Oct 2010 13:21:52 +0200
 
 libmodbus (2.0.3-1) intrepid; urgency=low
 

debian/control

@@ -1,12 +1,12 @@
 Source: libmodbus
-Distribution: hardy
 Priority: extra
 Maintainer: Stéphane Raimbault <stephane.raimbault@gmail.com>
-Standards-Version: 3.7.3
+Standards-Version: 3.9.1
 Section: libs
-Build-Depends: debhelper (>= 5.0.37.2),
+Build-Depends: debhelper (>= 6),
                cdbs (>= 0.4.43),
                autotools-dev,
+               libtool,
                dpkg-dev (>= 1.13.19)
 
 Package: libmodbus

debian/rules

@@ -1,3 +1,21 @@
 #!/usr/bin/make -f
 include /usr/share/cdbs/1/rules/debhelper.mk
 include /usr/share/cdbs/1/class/autotools.mk
+
+makebuilddir::
+	./autogen.sh
+
+clean::
+	rm -f Makefile.in
+	rm -f aclocal.m4
+	rm -f config.guess
+	rm -f config.h.in
+	rm -f config.sub
+	rm -f configure
+	rm -f depcomp
+	rm -f install-sh
+	rm -f ltmain.sh
+	rm -f missing
+	rm -f src/Makefile.in
+	rm -f tests/Makefile.in
+