Support the Resident Identity Card Number of People's Republic China.

Hi @arthurdejong ,

This is a implementation for supporting the Resident Identity Card Number of People's Republic China. The related knownledge and the checksum algorithm is from [Wikipeda](https://en.wikipedia.org/wiki/Resident_Identity_Card).

The script `getcnloc.py` could be used to download the location data of China mainland.

Could you review or merge it? Thanks.