Vendors: phlymail's Net_IDNA was replaced by PEAR Net_IDNA2.

The essence of the proposal:

There are four ways of encoding and decoding IDNs:

1. idn_to_ascii, idn_to_unicode and idn_to_utf8 (http://www.php.net/manual/en/ref.intl.idn.php). These functions are available since and bundled with PHP 5.3, so this is the best option for Yii2.

2. http://pear.php.net/package/Net_IDNA — obsolete and not maintained anymore PEAR library. It must not be used at all.

3. http://pear.php.net/package/Net_IDNA2 — normal and maintained PEAR library. Best choice for PHP < 5.3 code. According to it's SVN (http://svn.php.net/viewvc/pear/packages/Net_IDNA2/trunk/) it was updated 14 months ago (January, 2012).

4. http://phlymail.com/en/downloads/idna-convert.html — third party fork of the Net_IDNA (which was deprecated). According to it's website (http://phlymail.com/en/downloads/idna-convert.html) it was released at 2011-03-11.

We've discussed with @DaSourcerer which option is the best for Yii 1.1.* and came to opinion that it's better to switch to Net_IDNA2 since it's better maintained and unit tested.