publican: support out-of-source tree build

When srcdir!=builddir, there is no way to tell publican that the source
is in srcdir rather than builldir. The workaround is to copy the source
files from srcdir to builddir. To retain the en-US final destination
name, the source directory is renamed to en_US.

Tested-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Gaetan Nadon <memsize@videotron.ca>

doc/Wayland/en_US/Book_Info.xml

@@ -0,0 +1,34 @@
+<?xml version='1.0' encoding='utf-8' ?>
+<!DOCTYPE bookinfo PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
+<!ENTITY % BOOK_ENTITIES SYSTEM "Wayland.ent">
+%BOOK_ENTITIES;
+]>
+<bookinfo id="book-Wayland-Wayland">
+	<title>Wayland</title>
+	<subtitle>The Wayland display server</subtitle>
+	<productname>Documentation</productname>
+	<productnumber>0.1</productnumber>
+	<edition>0</edition>
+	<pubsnumber>0</pubsnumber>
+	<abstract>
+		<para>
+			Wayland is a protocol for a compositor to talk to
+			its clients as well as a C library implementation of
+			that protocol. The compositor can be a standalone
+			display server running on Linux kernel modesetting
+			and evdev input devices, an X application, or a
+			wayland client itself. The clients can be
+			traditional applications, X servers (rootless or
+			fullscreen) or other display servers.
+		</para>
+	</abstract>
+	<corpauthor>
+		<inlinemediaobject>
+			<imageobject>
+				<imagedata fileref="images/wayland.png" format="PNG" />
+			</imageobject>
+		</inlinemediaobject>
+	</corpauthor>
+	<xi:include href="Common_Content/Legal_Notice.xml" xmlns:xi="http://www.w3.org/2001/XInclude" />
+	<xi:include href="Author_Group.xml" xmlns:xi="http://www.w3.org/2001/XInclude" />
+</bookinfo>