Document fontBaseDir configuration entry and provide example.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/branches/fop-0_20_2-maintain@195467 13f79535-47bb-0310-9956-ffa450edef68

conf/userconfig.xml

@@ -10,9 +10,11 @@
 
 <configuration>
 
-<!--  NOT IMPLEMENTED
-basedir: normally the base directory is the directory where the fo file is 
-         located. if you want to specify your own, uncomment this entry
+<!--  
+baseDir: normally the base directory is the directory where the fo file is 
+         located. if you want to specify your own, uncomment this entry.
+         This value can also be a URL. Actually, the value is converted to 
+         a URL.
 -->
 <!-- 
   <entry>
@@ -21,6 +23,17 @@ basedir: normally the base directory is the directory where the fo file is
   </entry>
 -->
 
+<!--  
+fontBaseDir: Similar to baseDir, except that this value is used for fonts. If
+         it isn't specified, the value from baseDir is used.
+-->
+<!-- 
+  <entry>
+    <key>fontBaseDir</key>
+    <value></value>
+  </entry>
+-->
+
 <!--
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