get TApplicationException from thrift, not ttypes
get TApplicationException from thrift, not ttypes

since it doesn't show up in ttypes anymore for all Thrift versions, and
eventually it's going to disappear. not a great idea to rely on another
module's imports, anyway.

mshuler/cassandra-dbapi2,diezguerra/cassandra-dbapi2,maraca/cassandra-dbapi2,iGivefirst/cassandra-dbapi2,josh-mckenzie/cassandra-dbapi2,pcmanus/python-cql,CanWeStudio/cassandra-dbapi2,iflatness/cql,flowroute/cassandra-dbapi2,EnigmaCurry/cassandra-dbapi2,pandu-rao/cassandra-dbapi2,stanhu/cassandra-dbapi2