add HTTP redirect for renamed doc pages during "slave"->"worker" transition
add HTTP redirect for renamed doc pages during "slave"->"worker" transition

buildbot/buildbot-infra,buildbot/buildbot-infra,djmitche/buildbot-infra,seankelly/buildbot-infra,seankelly/buildbot-infra,buildbot/buildbot-infra,seankelly/buildbot-infra,djmitche/buildbot-infra,djmitche/buildbot-infra