FIX: report error when the only required conf of a module is not found or not visible
FIX: report error when the only required conf of a module is not found or not visible

git-svn-id: 29f0868cb983d9404d09bb30d964f948aae571fc@484128 13f79535-47bb-0310-9956-ffa450edef68

apache/ant-ivy,twogee/ant-ivy,twogee/ant-ivy,apache/ant-ivy,jaikiran/ant-ivy,thelateperseus/ant-ivy,twogee/ant-ivy,sbt/ivy,apache/ant-ivy,twogee/ant-ivy,apache/ant-ivy,jaikiran/ant-ivy,sbt/ivy,jaikiran/ant-ivy,jaikiran/ant-ivy,thelateperseus/ant-ivy