Numerous minor changes.
Numerous minor changes.

 - made strategies first class objects.
 - ... and added them to help and list commands.
 - ... and created a decorator to register them.
 - commented out currently unused 'decorator' dep.
 - updated a number of doc-strings to reflect changes.

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