poormanscron alternative

Issue Summary

hey there,

I just think that dropping poormanscron altogether is not very nice on the end users.

from a newbie point of view, cron IS complicated. and what is the point of ever having a CMS if you have to figure out how to do all the dirty work? ;)

so what I propose is: a way to configure cron jobs from within simplenews. and, if possible, a way to coexist with poormanscron. whattyasay?

I'd love to help, if I could write some decent PHP. but I am available for testing.

oh, and how does simplenews work on a multisite environment?
let's say we have Site A as the main site, with poormanscron but not simplenews;
then site B as an addon site, without poormanscron but with simplenews.

would this work for update checking AND newsletter firing?

cheers,
Luciano