Make master of scheduler compatible with current master of php-resque

It's been a while since the scheduler got updated, while php-resque slowly moved a long and has been improving. As I'll be relying on the resque infrastructure heavily for [the app of my startup](http://getrallypoint.com) I'm quite keen to get everything up to date again, with this "let's just make it work" PR as the beginning. 

Full credit goes to @robholmes who has obviously done all the work. There are some other forks out there, but this seems to be the one that addresses the core issues without touching too much of everything outside.