Pre-release of the systemd revision

Now the sysv revision is not complete, and even systemd revision still
needs to be rechecked.

Mark this as pre-release.

prologue/bookinfo.xml

@@ -7,8 +7,8 @@
 
 <bookinfo>
   <title>Linux From Scratch</title>
-  <subtitle revision='sysv'   > &version; 中文翻译版 </subtitle>
-  <subtitle revision='systemd'> &versiond; 中文翻译版 </subtitle>
+  <subtitle revision='sysv'   > &version; 中文翻译版（初稿）</subtitle>
+  <subtitle revision='systemd'> &versiond; 中文翻译版（初稿）</subtitle>
 
   <authorgroup>
     <author>