Factor out worker queue code from sync function
Factor out worker queue code from sync function

credativUK/vdirsyncer,mathstuf/vdirsyncer,untitaker/vdirsyncer,credativUK/vdirsyncer,untitaker/vdirsyncer,tribut/vdirsyncer,untitaker/vdirsyncer,hobarrera/vdirsyncer,mathstuf/vdirsyncer,hobarrera/vdirsyncer,tribut/vdirsyncer