man: generate configured paths in manpages

In particular, use /lib/systemd instead of /usr/lib/systemd in distributions
like Debian which still have not adopted a /usr merge setup.

Use XML entities from man/custom-entities.ent to replace configured paths while
doing XSLT processing of the original XML files. There was precedent of some
files (such as systemd.generator.xml) which were already using this approach.

This addresses most of the (manual) fixes from this patch:
http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/patches/Fix-paths-in-man-pages.patch?h=experimental-220

The idea of using generic XML entities was presented here:
http://lists.freedesktop.org/archives/systemd-devel/2015-May/032240.html

This patch solves almost all the issues, with the exception of:
- Path to /bin/mount and /bin/umount.
- Generic statements about preference of /lib over /etc.

These will be handled separately by follow up patches.

Tested:
- With default configure settings, ran "make install" to two separate
  directories and compared the output to confirm they matched exactly.
- Used a set of configure flags including $CONFFLAGS from Debian:
  http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/rules
  Installed the tree and confirmed the paths use /lib/systemd instead of
  /usr/lib/systemd and that no other unexpected differences exist.
- Confirmed that `make distcheck` still passes.

1 files changed, 12 insertions, 9 deletions

diff --git a/man/systemd.preset.xml b/man/systemd.preset.xml
index 2f9add8d6c..4667f9d616 100644
--- a/man/systemd.preset.xml
+++ b/man/systemd.preset.xml
@@ -1,6 +1,9 @@
 <?xml version="1.0"?>
 <!--*-nxml-*-->
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
+<!ENTITY % entities SYSTEM "custom-entities.ent" >
+%entities;
+]>
 <!--
   This file is part of systemd.
 
@@ -46,12 +49,12 @@
   </refnamediv>
 
   <refsynopsisdiv>
-    <para><filename>/etc/systemd/system-preset/*.preset</filename></para>
+    <para><filename>&pkgsysconfdir;/system-preset/*.preset</filename></para>
     <para><filename>/run/systemd/system-preset/*.preset</filename></para>
-    <para><filename>/usr/lib/systemd/system-preset/*.preset</filename></para>
-    <para><filename>/etc/systemd/user-preset/*.preset</filename></para>
+    <para><filename>&rootlibexecdir;/system-preset/*.preset</filename></para>
+    <para><filename>&pkgsysconfdir;/user-preset/*.preset</filename></para>
     <para><filename>/run/systemd/user-preset/*.preset</filename></para>
-    <para><filename>/usr/lib/systemd/user-preset/*.preset</filename></para>
+    <para><filename>&rootlibexecdir;/user-preset/*.preset</filename></para>
   </refsynopsisdiv>
 
   <refsect1>
@@ -125,7 +128,7 @@
     <para>If the administrator wants to disable a preset file supplied
     by the vendor, the recommended way is to place a symlink to
     <filename>/dev/null</filename> in
-    <filename>/etc/systemd/system-preset/</filename> bearing the same
+    <filename>&pkgsysconfdir;/system-preset/</filename> bearing the same
     filename.</para>
   </refsect1>
 
@@ -133,7 +136,7 @@
     <title>Example</title>
 
     <example>
-      <title>Default off example <filename>/usr/lib/systemd/system-preset/99-default.preset</filename>:</title>
+      <title>Default off example <filename>&rootlibexecdir;/system-preset/99-default.preset</filename>:</title>
 
       <programlisting>disable *</programlisting>
     </example>
@@ -144,7 +147,7 @@
     suchlike.</para>
 
     <example>
-      <title>A GNOME spin example <filename>/usr/lib/systemd/system-preset/50-gnome.preset</filename>:</title>
+      <title>A GNOME spin example <filename>&rootlibexecdir;/system-preset/50-gnome.preset</filename>:</title>
 
       <programlisting>enable gdm.service
 enable colord.service
@@ -162,7 +165,7 @@ enable avahi-daemon.*</programlisting>
     example like the one from the first example above.</para>
 
     <example>
-      <title>Administrator policy <filename>/etc/systemd/system-preset/00-lennart.preset</filename>:</title>
+      <title>Administrator policy <filename>&pkgsysconfdir;/system-preset/00-lennart.preset</filename>:</title>
 
       <programlisting>enable httpd.service
 enable sshd.service