Discourage insecure git URLs in documentation
Discourage insecure git URLs in documentation

Change the manpage to warn about unauthenticated URLs, and use
`https://` in examples.

pivotal-cf-experimental/bundler,jingweno/bundler,Eric-Guo/bundler,AiyionPrime/bundler,schaary/bundler,steved/bundler,byroot/bundler,Teino1978-Corp/Teino1978-Corp-bundler,carpodaster/bundler,bronzdoc/bundler,frsyuki/bundler,haonature888/bundler,ipmobiletech/bundler,haonaturel/bundler,seanlinsley/bundler,kohgpat/bundler,vemmaverve/bundler,chulkilee/bundler,Elffers/bundler,Teino1978-Corp/Teino1978-Corp-bundler,TimMoore/bundler,elovelan/bundler,frsyuki/bundler,neslom/bundler,haocafes/bundler,elovelan/bundler,anil826/bundler,pjump/bundler,roseweixel/bundler,dilumnavanjana/bundler,cstrahan/bundler,Wirachmat/bundler,christer155/bundler,jaym/bundler,EthanK28/bundler,dilumnavanjana/bundler,mvz/bundler,robinboening/bundler,Elffers/bundler,cdwort/bundler,kohgpat/bundler,mvz/bundler,bundler/bundler,simplybusiness/bundler,RochesterinNYC/bundler,ipmobiletech/bundler,PG-kura/bundler,zhangkuaiji/bundler,zhangkuaiji/bundler,twcctz500000/bundler,jasonkarns/bundler,asutoshpalai/bundler,chef/bundler,schaary/bundler,patvice/bundler,EasonYi/bundler,tgxworld/bundler,joshsoftware/bundler,pjump/bundler,cstrahan/bundler,ngpestelos/bundler,davydovanton/bundler,gregkare/bundler,smlance/bundler,danimashu/bundler,mpapis/bundler,bronzdoc/bundler,patvice/bundler,anil826/bundler,EasonYi/bundler,davydovanton/bundler,sideci-sample/sideci-sample-bundler,nju520/bundler,steved/bundler,asymmetric/bundler,philnash/bundler,Eric-Guo/bundler,masarakki/bundler,ximus/bundler,bundler/bundler,agis-/bundler,jaym/bundler,cdwort/bundler,jingweno/bundler,ligi/bundler,PG-kura/bundler,ligi/bundler,carpodaster/bundler,Wirachmat/bundler,JuanitoFatas/bundler,lmtim/bundler,h4ck3rm1k3/bundler,tgxworld/bundler,CorainChicago/bundler,wenderjean/bundler,TimMoore/bundler,ngpestelos/bundler,danimashu/bundler,simplybusiness/bundler,wenderjean/bundler,sideci-sample/sideci-sample-bundler,chulkilee/bundler,h4ck3rm1k3/bundler,suhastech/bundler,e2/bundler,neslom/bundler,mdorrance/bundler,EthanK28/bundler,smlance/bundler,joshsoftware/bundler,AiyionPrime/bundler,chef/bundler,suhastech/bundler,mpapis/bundler,mattbrictson/bundler-1,asutoshpalai/bundler,agis-/bundler,byroot/bundler,pivotal-cf-experimental/bundler,robinboening/bundler,lmtim/bundler,christer155/bundler,gregkare/bundler,ximus/bundler,CorainChicago/bundler,philnash/bundler,asymmetric/bundler,jasonkarns/bundler,mattbrictson/bundler-1,RochesterinNYC/bundler,haonature/bundler,masarakki/bundler,nju520/bundler,roseweixel/bundler,mdorrance/bundler,seanlinsley/bundler