New types, network performance, prepared_query API

• #error.codename (more readable errors)
• Redshift support (by allowing dynamic typecache update fail)
• Aggregate small binary packets in to one in epgsql_sock (network performance improvement)
• Handle situations, when server initiate connection close
• prepared_query APIs (useful when you need to execute one query many times with different parameters)
• array of records type support
• jsonb type support