Changed the reconnection logic to reduce the flood of reconnects.

As per my rant on the gocql mailing list. Sorry Chris this address the connection flooding when an invalid keyspace is defined.

Also in conn_test in the TestConnClose I commented out the connection closing as I did not understand the reason this was being done. Connections are closed with the kill query and then the code I commented out reached into the library to delibrately close connections. I just want to understand this as this causes the test to fail with 3 connections in the pool instead of the expected 2.

I cleaned up a lot of Cluster Config parameters that were related to the old connection retry logic.

The one improvement I can see right now is implementing debouncing of calls to fillPool() so that its not chugging away and consuming resources.