Ignore reference errors in the control conn

These frequently happen when the cluster is being shutdown
and the control connection is refreshing the schema or ring topology
Undo param passing for non-prepared statements

There are a couple of reasons this can't be supported at the moment.

The first, and most serious, is that the passed parameters must be in
their binary form, not a string representation.  For non-prepared
statements, the driver doesn't know what Cassandra types it's dealing
with, so the best it can do is map python types to string formatting
functions (see cql_encoders).  It can't tell if it should convert 123 to
the Int32Type binary representation or the IntegerType binary
representation.  (Likewise for FloatType and DoubleType.)

Second, Cassandra doesn't accept a map of parameter names to parameter
values, so even though there are named placeholders, the driver would
have to parse the query string to handle a dict of parameters.
Actually fix BatchType enums this time
Correct v2 ExecuteMessage encoding
Bind non-prepared batch subqueries client-side