QPID-5764: add note detaling the move to the maven build for future releases

merged from trunk r1594176


git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/0.28@1594179 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/qpid/java/build.xml b/qpid/java/build.xml
index f73c5b3..90d26de 100644
--- a/qpid/java/build.xml
+++ b/qpid/java/build.xml
@@ -104,6 +104,16 @@
       <available file="${build.failed}"/>
     </condition>
 
+    <echo>
+    -----------------------    NOTE    ---------------------------
+    The Java components are transitioning to using a Maven based
+    build process, this build process will be removed in the 0.30
+    release. A preview of the new Maven build is available
+    alongside this one, simply requiring -Denable=true be specified
+    in any Maven commands used.
+    ---------------------------------------------------------------
+    </echo>
+
     <fail if="failed" message="TEST SUITE FAILED"/>
 
   </target>
@@ -172,6 +182,15 @@
   <target name="build" depends="retrieve-dependencies" description="build the project">
     <iterate target="build"/>
     <antcall target="manifest"/>
+    <echo>
+    -----------------------    NOTE    ---------------------------
+    The Java components are transitioning to using a Maven based
+    build process, this build process will be removed in the 0.30
+    release. A preview of the new Maven build is available
+    alongside this one, simply requiring -Denable=true be specified
+    in any Maven commands used.
+    ---------------------------------------------------------------
+    </echo>
   </target>
 
   <target name="prepare">