use php.net as host, to allow mirror redirects

Prevents us2.php.net from getting all of the traffic.
Merge pull request #5 from docker-library-php/use-php-mirrors

use php.net as host, to allow mirror redirects
Added compile option --with-mysqli in versions with Apache
Added mysql PDO support to compile flags in versions with Apache
Merge pull request #7 from mattva01/master

Added compile option --with-mysqli in versions with Apache
Simplify "-apache" images by using the Debian apache2 packages
Merge pull request #9 from infosiftr/simpler-apache

Simplify "-apache" images by using the Debian apache2 packages
Update versions
Update 5.6 version - fix #11

Signed-off-by: Rogerio Prado de Jesus <rogeriopradoj@gmail.com>
Merge pull request #12 from rogeriopradoj/fix-11

Update 5.6 version