Add long values support

[xdars]

During working with Telegram Bot API with cJSON library for parsing values, I've faced an issue. The issue is this: I was unable to get identifier value from response - -1001182111522 - obviously, according to cJSON parse_number function, such value was never going to be stored in item->valueint. Sure, let it go - but why not try to store the value anyways, but as long?