Shorten counter sub group names - long term fix

[vrushalic]

As noted in #34 , we need a long term fix for dealing with counter subgroup names. Presently hRaven stores the subgroup name for each counter in the column name. The idea here is to come up with a naming scheme for counter sub group names since there seem to be a lot of repetition of org.apache.hadoop.mapred.XX.YY for every counter. So we could map org.apache.hadoop.mapred. to something like o.a.h.m. But that is a bigger fix since we first need an audit of all existing counter sub group names, come up with map and then we need to change every place where counters are being written, queried for and returned and then rewrite the existing data in hbase as well.