Correct a couple of minor build details

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/integration/solr-4.x/trunk@1570108 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/build.xml b/build.xml
index 1585ca3..75c5f3b 100644
--- a/build.xml
+++ b/build.xml
@@ -132,7 +132,7 @@
       </tar>
   </target>
 
-  <target name="image" depends="create-source-zip,create-source-tar,create-bin-zip,create-bin-tar"/>
+  <target name="image" depends="create-source-zip,create-source-tar,create-bin-zip,create-bin-tar" if="downloaded"/>
 
   <target name="help">
     <echo level="info">
@@ -148,9 +148,8 @@
 test       - Run the tests
 image      - Package the sources and binaries
 
-Prerequisites: This build requires Subversion (svn) to be
-installed, and svn internet access to the Apache repository.
-It also requires Java jdk1.6.0 or above.
+Prerequisites: This build Java jdk1.6.0 or above,
+and Apache Ivy 2.2 or above.
     </echo>
   </target>