docs: make manual page versioning automatic

In same go mark the manual page in System Administration selection.

.gitignore

@@ -22,5 +22,6 @@ stamp-h1*
 /ChangeLog
 /INSTALL
 /mtr
+/mtr.8
 
 /mtr-*.tar.gz

Makefile.am

@@ -1,7 +1,24 @@
 EXTRA_DIST = SECURITY img/mtr_icon.xpm
 
 sbin_PROGRAMS = mtr
+
+PATHFILES =
+CLEANFILES = $(PATHFILES)
+EXTRA_DIST += $(PATHFILES:=.in)
+edit_cmd = sed \
+	-e 's|@VERSION[@]|$(VERSION)|g'
+
+$(PATHFILES): Makefile
+	@ rm -f $@ $@.tmp
+	$(AM_V_at) $(MKDIR_P) $$(dirname $@)
+	$(AM_V_GEN) srcdir=''; \
+		test -f ./$@.in || srcdir=$(srcdir)/; \
+		$(edit_cmd) $${srcdir}$@.in >$@.tmp
+	@ mv $@.tmp $@
+
 dist_man_MANS = mtr.8
+PATHFILES += mtr.8
+
 install-exec-hook: 
 	`setcap cap_net_raw+ep $(DESTDIR)$(sbindir)/mtr` \
 	|| chmod u+s $(DESTDIR)$(sbindir)/mtr

mtr.8 → mtr.8.in

@@ -1,4 +1,4 @@
-.TH MTR 8 "July 12, 2014" "mtr" "mtr"
+.TH MTR 8 "@VERSION@" "mtr" "System Administration"
 .SH NAME
 mtr \- a network diagnostic tool
 .SH SYNOPSIS