Fixed https://github.com/NICTA/scoobi/issues/308: MR job numbering broken in HadoopMode for job plans with more than 1 layer

Fixed by computing, at each layer, the total number
of MSCRs in all previous layers, and plumbing that
down to configureMscr, where the "Step X of Y"
gets configured.
Fixed https://github.com/NICTA/scoobi/issues/306: In-memory mode does not keep track of hadoop counters
Issue #303: Updated hadoop-* dependency versions for -hadoop2 to 2.2.0
In order to get the Scoobi WordCount example working on a CDH5-beta1 cluster,
I've changed the hadoop-* dependency versions from 2.1.0.2.0.5.0-67 to 2.2.0
and removed the dependency on the hortonworks repository at the same time.
Issue #303: Added hadoop2 classifier to avro dependency