Move up Hadoop in pom.xml and add back protobufs
As Hadoop 1.0.4 doesn't use protobufs, we can't exclude
protobufs from Spark always. This change tries to order the dependencies
so that the shader first picks up Hadoop's protobufs over Mesos.
Merge pull request #48 from shivaram/master

Move up Hadoop in pom.xml and add back protobufs