v9.0.0

Changes:

1. JSON support.
2. openssl updated to v0.9
3. tcp_keepalive_timeout_ms option added.

JSON Support

1. FromValue is implemented for rustc_serialize::json::Json and for Unserialized<T> where T: Decodable:

   #[derive(RustcDecodable)]
   struct DecodableStruct {
       // ...
   }
   // ...
   let (Unserialized(val),): (Unserialized<DecodableStruct>,)
       = from_row(row_with_single_json_column);

2. From<Json> and From<Serialized<T>> where T: Encodable is implemented for Value:

   #[derive(RustcEncodable)]
   struct EncodableStruct {
       // ...
   }
   // ...
   conn.prep_exec("INSERT INTO table (json_column) VALUES (?)",
                  (Serialized(encodable_struct_instance),));