engine: reintroduce dumb scheduler
engine: reintroduce dumb scheduler

Add the old offer-to-all scheduler back as "dumbReconciler". This has
been mostly unmodified, with the exception of replacing the partitioning
of machine IDs with a NOP. Jobs are offered to all machines.

This code was pulled from commit 704df23.

endocode/fleet,WPMedia/fleet,mwhooker/fleet,hhoover/fleet,endocode/fleet,dalbani/fleet,paveltiunov/fleet,mischief/fleet,improbable-io/fleet,dalbani/fleet,dongsupark/fleet,improbable-io/fleet,wuqixuan/fleet,esatterwhite/fleet,webwlsong/fleet,mwhooker/fleet,improbable-io/fleet,esatterwhite/fleet,ecnahc515/fleet,giantswarm/fleet,webwlsong/fleet,endocode/fleet,mookjp/fleet,ecnahc515/fleet,flandr/fleet,mwitkow-io/fleet,giantswarm/fleet,bcwaldon/fleet,giantswarm/fleet,coreos/fleet,thepwagner/fleet,bcwaldon/fleet,wuqixuan/fleet,mwitkow-io/fleet,coreos/fleet,jonboulle/fleet,mwitkow/fleet,octoblu/fleet,flandr/fleet,mookjp/fleet,bcwaldon/fleet,octoblu/fleet,jonboulle/fleet,dalbani/fleet,thepwagner/fleet,bviswana101/fleet,WPMedia/fleet,dongsupark/fleet,coreos/fleet,hhoover/fleet,dongsupark/fleet,mwitkow/fleet,bviswana101/fleet,mischief/fleet,paveltiunov/fleet,ecnahc515/fleet,jonboulle/fleet