We've patched GridMix (a contribution in Hadoop) because it was broken under Java 7.
We can stop applying this custom patch when (if?) GridMix is patched in the Hadoop versions
we support.

We've also patched build.xml of hadoop-0.20.205.0 because its 'jsvc' target is broken.
The patch is obtained from https://issues.apache.org/jira/browse/HADOOP-7698.