build: Generate ChangeLog in 'make dist', ZIP automatically

Change 'make dist' to generate the Git ChangeLog file, that way it doesn't
have to be manually updated nor kept in Git which causes unnecessary work.

Also change 'make dist' to invoke 'dist-zip' automatically to generate a
ZIP as well as a .tar.gz.

Thanks to http://live.gnome.org/Git/ChangeLog for the inspiration to
automatically generate ChangeLog.

Makefile.am

@@ -9,6 +9,18 @@ $(top_srcdir)/foreign/xmlParser/xmlParser.cpp \
 $(top_srcdir)/foreign/xmlParser/xmlParser.hpp
 
 dist-hook:
+	@if test -d "$(srcdir)/.git"; \
+	then \
+		echo Creating ChangeLog && \
+		( cd "$(top_srcdir)" && \
+		  echo '# Generated by Makefile. Do not edit.'; echo; \
+		  $(top_srcdir)/config/missing --run git log --stat ) > ChangeLog.tmp \
+		  && mv -f ChangeLog.tmp $(top_distdir)/ChangeLog \
+		  || ( rm -f ChangeLog.tmp ; \
+		       echo Failed to generate ChangeLog >&2 ); \
+	else \
+		echo A git clone is required to generate a ChangeLog >&2; \
+	fi
 	-cp $(top_srcdir)/builds/redhat/zeromq.spec $(distdir)/zeromq.spec
 	-sed s/\@PACKAGE_VERSION\@/@PACKAGE_VERSION@/ -i $(distdir)/zeromq.spec
 	-rm -rf $(distdir)/foreign/openpgm/@pgm_basename@

configure.in

@@ -11,7 +11,7 @@ AC_INIT([zeromq],[2.0.9],[zeromq-dev@lists.zeromq.org])
 AC_CONFIG_AUX_DIR(config)
 AC_CONFIG_MACRO_DIR(config)
 AM_CONFIG_HEADER(src/platform.hpp)
-AM_INIT_AUTOMAKE(tar-ustar)
+AM_INIT_AUTOMAKE(tar-ustar dist-zip foreign)
 
 # This defines PACKAGE_VERSION_... in src/platform.hpp
 PV_MAJOR=`echo $PACKAGE_VERSION | cut -d . -f 1`