[backend] fix last archlinux publisher change

simply replacing symlink with link is not enough...
[backend] no longer send SRCSRV_START notification

It no longer has a valid payload and as such rather spam (and we couldn't
come up with a valid use case)
[api] remove unused production_test environment

(was never even ported to rails 3)
[api] move the actual auto accept out of the clock daemon

The clock daemon stops while doing jobs, so everything that takes
longer than a couple of milliseconds should only trigger a delayed
job

While I was at it, I moved the rather huge and clumpsy BsRequest.collection
function into a model on its own (to be further refactored)