CassandraCounterBatchingBolt takes Type parameters

This allows CassandraCounterBatchingBolt to write to rows that have
rowkeys with a type other than string.

Had also to correct the TupleCounterMapper and the Astyanax client.

The DefaultTupleCounterMaper uses String for rowkeys and columnkeys.

Corrected the CassandraBoltTest to work with this alterations.
Upgrade to 0.9.0-rc2
Merge branch 'master' of github.com:hmsonline/storm-cassandra
Update README.md
Merge pull request #37 from abhinav-nigam/patch-1

Update README.md
Merge branch 'master' of https://github.com/rjsteixeira/storm-cassandra
Merge branch 'master' of github.com:hmsonline/storm-cassandra
Fixed counter test.

It was failing after the first run because the counter column family wasn't reset.
Merge branch 'master' of github.com:hmsonline/storm-cassandra
Updated to 0.9.0.1