re-enabled known failing cases
testdir_multi_jvm/test_ddply_plot2.py fails with
[2014-08-24 00:35:15.089058] exec_query parameters: {'str': 'a1 = ddply(r.hex, c(1,2), func1)'}
[2014-08-24 00:35:15.089151] 12:35:20.798 FJ-119-13 ERRR WATER: Missing vector #0 (C1) during Frame fetch: $04ff0b268d63ffffffff5b18b8585d38efa76247b464e6$X6C
[2014-08-24 00:35:37.281899] +                                  java.util.concurrent.ExecutionException: java.lang.NullPointerException