Make the SpooledJobFiles methods operate on real ClassAds.

The job router uses real ClassAds instead of compat ClassAds, and it
uses the SpooledJobFiles methods. This changes eliminates some needless
copying of ClassAds in the job router.
Don't unparse ad in dPrintAd() when debug level means it won't print.
Set the proper HoldReasonCode on job submission in the job router.
Use a more efficient form of DCSChedd::removeJobs() in the job router.