* Updated php.net link for some MemCache properties [skip ci]
* Changed protocol to https for links to php.net in comments
* Changed protocol to https for links to php.net in code
* Changed www.php.net (http) to secure.php.net (https) in comments
* Changed www.php.net (http) to secure.php.net (https) in code
* Changed protocol to https for links to php.net in UPGRADE.md
* Changed protocol to https for links to pecl.php.net in comments
* Changed us.php.net to secure.php.net (https) in comments
* Changed protocol to https for links to php.net in docs
* Changed www.php.net (http) to secure.php.net (https) in docs
* Changed protocol to https for links to pecl.php.net in docs
* Changed ru/jp.php.net to secure.php.net (https) in docs
Don't sure about russian guide: is this links meant to be for guide on russian, or not?
* link fix in Doc/guide/README.md [ci skip]
* doc/guide/start-databases.md link fixed [ci skip]
* docs/guide/start-gii.md link fixed [ci skip]
* docs/guide/start-looking-ahead.md link fixed [ci skip]