Drop documentation dependency on local() from local_per_host() and clarify fail kwarg.
Drop documentation dependency on local() from local_per_host() and clarify fail kwarg.

bitprophet/fabric,haridsv/fabric,tolbkni/fabric,amaniak/fabric,opavader/fabric,akaariai/fabric,fernandezcuesta/fabric,qinrong/fabric,felix-d/fabric,tekapo/fabric,StackStorm/fabric,getsentry/fabric,rane-hs/fabric-py3,rbramwell/fabric,SamuelMarks/fabric,elijah513/fabric,pashinin/fabric,simon-engledew/fabric,hrubi/fabric,kmonsoor/fabric,bspink/fabric,cmattoon/fabric,ericholscher/fabric,rodrigc/fabric,raimon49/fabric,mathiasertl/fabric,itoed/fabric,cgvarela/fabric,pgroudas/fabric,bitmonk/fabric,jaraco/fabric,kxxoling/fabric,xLegoz/fabric,MjAbuz/fabric,askulkarni2/fabric,likesxuqiang/fabric,ploxiln/fabric,sdelements/fabric,TarasRudnyk/fabric