Add the manual to the build making it fully optional unless karaf is being released

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@824796 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/karaf/pom.xml b/karaf/pom.xml
index 612b474..81d8388 100644
--- a/karaf/pom.xml
+++ b/karaf/pom.xml
@@ -46,6 +46,7 @@
         <module>demos</module>
         <module>itests</module>
         <module>tooling</module>
+        <module>manual</module>
     </modules>
 
     <scm>