Store IPv4 and IPv6 address along with user votes

[mice-sk]

We need to store IP addresses of users who vote in the poll (regardless if anonymous or authenticated users) in order to provide means to detect automated voting bots.

On top of storing IPv4 addresses, propose that we implement IPv6 support right from the start.

[teo-sk]

This still needs to be enhanced by storing IP addresses as int/long data types, and by storing either both IPv4 and IPv6 as separate columns (need to fill the correct column after input validation) or by converting IPv4 to IPv6

References:
http://php.net/manual/en/function.inet-pton.php
http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_inet-aton
https://groups.google.com/forum/?fromgroups#!topic/doctrine-user/07mBafTJtTM