Refactored Hadoop port. The new port doesn't require patching Hadoop
(i.e., it's a self contained Hadoop contrib) and lets you use existing
schedulers (e.g., the fair scheduler or capacity scheduler)!  The
tradeoff, however, is that it doesn't take as much advantage of the
fine-grained nature of a Mesos task (i.e., there is no longer a 1-1
mapping between a Mesos task and a map/reduce task).

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1439225 13f79535-47bb-0310-9956-ffa450edef68