Buildd Manager Upload Decoupling

When processing completed uploads, the buildd manager puts the binary package in the upload queue. calls process-upload.py (using Popen) and then does post-upload processing that sets on the build: the buildlog, the builder used, its dependencies, date built and build duration. It also post-processes upload failures and sets the upload log.

The processing should take place entirely in the upload processor so that the buildd-manager can throw the binary package in the queue and forget about it, this reducing the latency when scanning the build farm.