Bug 752836 - Don't build Thunderbird for Instantbird pushes. r=catlee
Bug 980890: disable skip-spot logic to get builds going again. r=bustage
nobug: don't classify slaves that don't have names (or connected slave objects).

this is causing some spurious exceptions in twisted logs. it's a bit of a
mystery how slaves without connected slave objects are considered available...
Merge branch 'master' into fx-mh-builds