This also removes one dependency on the winapi crate. The current
version of the time crate also depends on winapi, but work is being done
to replace that version with 0.2 to remove the winapi dependency.
Replace `Row::get` by `Row::get_checked`,
And rename original `Row::get` to `Row::get_unwrap`.
`Stmt::query_map`, `Stmt::query_map_named`, `Stmt::query_row`,
`Conn::query_row` and `Conn::query_row_named` callback parameter must return a `Result`.