Invalid cast from object to int on long data type.
This is tested against Npgsql 220.127.116.11 (current version available through Nuget)
Fixes invalid cast exception on Postgres Count
The postgres count operation returns a long. Attempting to cast
directly from type object to int throws an invalid cast exception.
Casting first to a long, then casting to an int gets around this
error without changing the Massive API.
added code comments
fixed comment typo