New Parameters: ssl_timeout / nginx_vhosts_defaults 

Added new Parameters:
 * ```$ssl_timeout``` (nginx: ssl_session_timeout) on ```nginx::resource::vhost``` define
 * ```$nginx_vhosts_defaults``` on ```nginx``` class: This allows to set defaults for all created vhosts through the ```create_resource``` function call. This reduces the hiera yaml code immensely, when creating large lists of vhosts. 

Analogous Parameter to ```$nginx_vhosts_defaults``` could/should be introduced for ```...mailhosts```, ```...locations```, ...