Move manual page generation to maintainer mode

The page will be being shipped pre-built in official tars.

Also provides an option to disable manpage generation/installation, as
requested for the main firehol package, to allow users to build the program
with minimal extra infrastructure.

Makefile.am

@@ -24,7 +24,10 @@ iprange_DESCRIPTION = "manage IP ranges"
 
 bin_PROGRAMS = iprange
 dist_noinst_DATA = iprange.spec
+
+if ENABLE_MAN
 man_MANS = iprange.1
+endif
 
 iprange_SOURCES = iprange.c
 
@@ -33,9 +36,10 @@ EXTRA_DIST = \
 	README.md \
 	iprange-9999.ebuild \
 	autogen.sh \
-	iprange.1 \
+	$(man_MANS) \
 	$(NULL)
 
+if MAINTAINER_MODE
 %.1: %
 	$(HELP2MAN) \
 			-s 1 \
@@ -44,3 +48,4 @@ EXTRA_DIST = \
 			-n $(if $($(subst -,_,$*)_DESCRIPTION), $($(subst -,_,$*)_DESCRIPTION), "manual page for $*") \
 			-o $@ \
 		$(top_builddir)/$<
+endif

configure.ac

@@ -14,10 +14,24 @@ PACKAGE_RPM_RELEASE="0.0.$(echo VERSION_SUFFIX | sed s/^_//)"
 
 AC_INIT([iprange], VERSION_NUMBER[]VERSION_SUFFIX)
 
+AC_ARG_ENABLE([man],
+              [AS_HELP_STRING([--disable-man], [disable manpage installation @<:@enabled@:>@])],
+              ,
+              [enable_man="yes"])
+AM_CONDITIONAL([ENABLE_MAN], [test "${enable_man}" = "yes"])
+
 AM_MAINTAINER_MODE([disable])
 if test x"$USE_MAINTAINER_MODE" = xyes; then
 AC_MSG_NOTICE(***************** MAINTAINER MODE *****************)
 PACKAGE_BUILT_DATE=$(date '+%d %b %Y')
+
+AX_NEED_PROG([HELP2MAN],[help2man],[])
+else
+  if test ! -f iprange.1; then
+    if test x"$enable_man" = xyes; then
+      AC_MSG_ERROR([docs not built, use '--disable-man' or --enable-maintainer-mode])
+    fi
+  fi
 fi
 
 PACKAGE_RPM_VERSION="VERSION_NUMBER"
@@ -32,7 +46,6 @@ AM_INIT_AUTOMAKE
 AC_CANONICAL_HOST
 AC_PROG_CC
 AC_PROG_INSTALL
-AX_NEED_PROG([HELP2MAN],[help2man],[])
 AC_ARG_ENABLE(
 	[pedantic],
 	[AS_HELP_STRING([--enable-pedantic], [enable pedantic compiler warnings])],