Bug fixes and enhancements.
Bug fixes and enhancements.

* id connections.
* introduce options.max_query to allow separate and configurable query timeouts.
* emit error event on thrift error.
* long query watch logs a trace when any query takes more than 10s.
* pooled connections need to quietly tear down transport connections when being reconnected.
* fix recoverable error logic in PooledConnection.execute.
* Make PooledConnection.execute() re-execution calls explicit (saw some strange inheritance problems when execute() was overloaded with different parameters).

racker/node-cassandra-client,racker/node-cassandra-client