Handling SetPartitioner failure

Sometimes, when their is connection drop the SetPartitioner object fails
to be created possibly due to SessionExpiredError. The object is set to
FAILURE in that case. This way the client tries to create object again

Using internal _state and manually getting state related properties that
makes code more readable. Updated tests accordingly.
hosts as cmd-line arg

also changing time_boundary=15 as that is used in otter
updated version for new partition error change
Merge pull request #5 from rackerlabs/partition_error

Handling SetPartitioner failure