Cron support

[ephigenie]

Indeed - the templates are ready - but there are some things to think over before implementing - the first one :
- What about security ?
if someone is using cron's they've to be executed like cgi-bin's but most of us will have disabled this feature atm because it is horrible insecure because every user may execute scripts without being chrooted etc.

- Shall cronjobs only consist of php-scripts executed ? so that the php.ini gets used or maybe a url is triggered ... would that help ?