* Set value for std with c99 to avoid compile error on CentOS7.

* Get parameter from stack by same sequence.

* Add performance test.

Connector is implemented by lua51 but luajit and ffi are not included. Connection pool is not implemented yet. It is a raw demonstration at present and not verified on production environment.

Field names and values are both returned. Client application gets value by field name. It runs as convention except that bool type is returned as one byte,tiny integer. Bool type will be returned in future if tiny integer causes confusion.