Implemented: EZP-23343: Add support for IPv6 addresses and address ranges to DebugByIP feature in eZDebug class to enable debug output

Hello,

Recently we tried on our localhost development environment to enable the DebugByIP feature using my computers localhost IPv6 IP Address '::1'. 

The DebugOutput would not display with the IPv6 IP Address '::1' entered properly into the settings configuration and all caches cleared.

We traced the problem to code in eZDebug::isAllowedByCurrentIP() where it tested only for IPv4 IP Addresses and not IPv6 IP Addresses.

We then wrote replacement code to enable debug output on a computer which uses IPv6 IP Addresses.

We also wrote replacement code to support IPv6 IP Address Ranges to display DebugOutput to an entire subnet (IP Address Range).

We write today to respectfully request your review of our code improvements which provide for DebugByIP / eZDebug / DebugOutput support of IPv6 Addresses and Address ranges.

We have created a new issue ticket about this feature request, you can find it here: https://jira.ez.no/browse/EZP-23343

Please review and let us know what you think.

Thank you for your continued support!

Cheers,
Brookins Consulting
This line is too long imho.

Instead of writing 4 lines of comments, I'd use meaningful variables for the compared elements. Maybe:

```php
$maskedBinaryNetwork = substr( self::packedToBin( inet_pton( $ipAddresRangeNetwork ) ), 0, $networkMaskBits );
$maskedBinaryIpAddress = substr( self::packedToBin( inet_pton( $ipAddress ) ), 0, $networkMaskBits ) );
return $maskedBinaryNetwork === $maskedBinaryIpAddress;
```