added reference to developer's guide for more info on why Ant 1.6 is required for building
added reference to developer's guide for more info on why Ant 1.6 is required for building

git-svn-id: d201ecbade8cc7da50e7bffa1d709f7a0d92be7d@179435 13f79535-47bb-0310-9956-ffa450edef68

anzhdanov/seeding-realistic-concurrency-bugs,mureinik/commons-lang,rikles/commons-lang,rikles/commons-lang,anzhdanov/seeding-realistic-concurrency-bugs,anzhdanov/seeding-realistic-concurrency-bugs,mureinik/commons-lang,rikles/commons-lang,mureinik/commons-lang