Connection Pooler for mongodb similar to PostgreSQL FDW.
This will avoid multiple connection and disconnection to
MongoDB Server. FDW's Options functions separated from
"mongo_fdw.c" and placed in "option.c" file. The newly
created connection's pooling functions placed into
"connection.c" file.
Plemove DeserializeDocument and SerializeDocument functions which are
causing the server to crash while query is used in any container,
i.e in PlpgSQl function.
Write support (INSERT/UPDATE/DELETE).
MongoDB's Meta Driver support added.