Set php_*values and php_*flags when provided

When php_*values or php_*flags are set they will be added to the pool config.
````
    php_values(
      'session.save_path' => "/tmp/sessions",
      'upload_tmp_dir' => "/tmp/upload"
    )
    php_admin_flags(
      'log_errors' => 'on'
    )
````
results in
````
php_value[session.save_path] = /tmp/sessions
php_value[upload_tmp_dir] = /tmp/upload
php_admin_flag[log_errors] = on
````