Remove APC and replace with Zend Opcache

[Slavik]

With Zend Opcache now open source and as part of the PHP 5.5 branch, maybe its time to drop APC from the PHP Compile page and update it to Zend Opcache?

 

[eva2000]

I would make it optional choice for installation rather than remove. APC Cache might be needed for user data caching which Zend OPCache doesn't support. While you can use Zend OPCache + APCu fork for data caching, it still is added work and few folks are reporting APCu fork data caching not working as expected compared to APC Cache user data caching.