TrivialRebase: Support alternative ssh executable
TrivialRebase: Support alternative ssh executable

like plink.

Two arguments are added:

--ssh - ssh executable to be used (default: "ssh")
--ssh-port-flag - port flag for ssh (default: "-p")

Since ssh-port-flag receives a flag it can only be
used with --arg=value notation

plink requires "--ssh plink --ssh-port-flag=-P"

Change-Id: I7f494e099de9a9877a3336fcd4e735a9d9dfd921

thinkernel/gerrit,midnightradio/gerrit,zommarin/gerrit,bpollack/gerrit,gcoders/gerrit,thesamet/gerrit,renchaorevee/gerrit,zommarin/gerrit,netroby/gerrit,basilgor/gerrit,Team-OctOS/host_gerrit,netroby/gerrit,gracefullife/gerrit,dwhipstock/gerrit,jackminicloud/test,pkdevbox/gerrit,qtproject/qtqa-gerrit,pkdevbox/gerrit,gcoders/gerrit,WANdisco/gerrit,renchaorevee/gerrit,joshuawilson/merrit,TonyChai24/test,MerritCR/merrit,Seinlin/gerrit,gcoders/gerrit,GerritCodeReview/gerrit,hdost/gerrit,WANdisco/gerrit,MerritCR/merrit,gerrit-review/gerrit,gerrit-review/gerrit,jackminicloud/test,qtproject/qtqa-gerrit,netroby/gerrit,Distrotech/gerrit,MerritCR/merrit,dwhipstock/gerrit,quyixia/gerrit,dwhipstock/gerrit,thinkernel/gerrit,TonyChai24/test,ckamm/gerrit,gerrit-review/gerrit,supriyantomaftuh/gerrit,supriyantomaftuh/gerrit,basilgor/gerrit,TonyChai24/test,basilgor/gerrit,jackminicloud/test,gracefullife/gerrit,joshuawilson/merrit,Overruler/gerrit,netroby/gerrit,Distrotech/gerrit,supriyantomaftuh/gerrit,bpollack/gerrit,midnightradio/gerrit,qtproject/qtqa-gerrit,Saulis/gerrit,thesamet/gerrit,hdost/gerrit,Saulis/gerrit,renchaorevee/gerrit,MerritCR/merrit,netroby/gerrit,TonyChai24/test,quyixia/gerrit,Team-OctOS/host_gerrit,pkdevbox/gerrit,Overruler/gerrit,renchaorevee/gerrit,TonyChai24/test,ckamm/gerrit,hdost/gerrit,Distrotech/gerrit,Overruler/gerrit,Seinlin/gerrit,WANdisco/gerrit,hdost/gerrit,gracefullife/gerrit,anminhsu/gerrit,dwhipstock/gerrit,quyixia/gerrit,hdost/gerrit,thinkernel/gerrit,zommarin/gerrit,qtproject/qtqa-gerrit,bpollack/gerrit,thesamet/gerrit,MerritCR/merrit,GerritCodeReview/gerrit,Team-OctOS/host_gerrit,gerrit-review/gerrit,anminhsu/gerrit,GerritCodeReview/gerrit,Seinlin/gerrit,MerritCR/merrit,GerritCodeReview/gerrit,bootstraponline-archive/gerrit-mirror,joshuawilson/merrit,netroby/gerrit,Team-OctOS/host_gerrit,thinkernel/gerrit,Seinlin/gerrit,thinkernel/gerrit,midnightradio/gerrit,anminhsu/gerrit,Seinlin/gerrit,quyixia/gerrit,gcoders/gerrit,bpollack/gerrit,gerrit-review/gerrit,jackminicloud/test,ckamm/gerrit,bpollack/gerrit,zommarin/gerrit,ckamm/gerrit,dwhipstock/gerrit,supriyantomaftuh/gerrit,WANdisco/gerrit,pkdevbox/gerrit,gcoders/gerrit,renchaorevee/gerrit,Team-OctOS/host_gerrit,hdost/gerrit,Distrotech/gerrit,thesamet/gerrit,supriyantomaftuh/gerrit,bootstraponline-archive/gerrit-mirror,WANdisco/gerrit,gcoders/gerrit,TonyChai24/test,Saulis/gerrit,Saulis/gerrit,thinkernel/gerrit,Distrotech/gerrit,qtproject/qtqa-gerrit,Seinlin/gerrit,dwhipstock/gerrit,joshuawilson/merrit,thesamet/gerrit,WANdisco/gerrit,quyixia/gerrit,midnightradio/gerrit,bpollack/gerrit,basilgor/gerrit,thesamet/gerrit,bootstraponline-archive/gerrit-mirror,Saulis/gerrit,supriyantomaftuh/gerrit,supriyantomaftuh/gerrit,bootstraponline-archive/gerrit-mirror,gracefullife/gerrit,WANdisco/gerrit,gracefullife/gerrit,zommarin/gerrit,gerrit-review/gerrit,anminhsu/gerrit,gerrit-review/gerrit,Team-OctOS/host_gerrit,GerritCodeReview/gerrit,joshuawilson/merrit,Overruler/gerrit,GerritCodeReview/gerrit,bootstraponline-archive/gerrit-mirror,thesamet/gerrit,gcoders/gerrit,pkdevbox/gerrit,anminhsu/gerrit,midnightradio/gerrit,Overruler/gerrit,Saulis/gerrit,Seinlin/gerrit,renchaorevee/gerrit,joshuawilson/merrit,anminhsu/gerrit,jackminicloud/test,qtproject/qtqa-gerrit,quyixia/gerrit,dwhipstock/gerrit,basilgor/gerrit,anminhsu/gerrit,midnightradio/gerrit,MerritCR/merrit,TonyChai24/test,pkdevbox/gerrit,quyixia/gerrit,Distrotech/gerrit,hdost/gerrit,Team-OctOS/host_gerrit,Overruler/gerrit,GerritCodeReview/gerrit,jackminicloud/test,GerritCodeReview/gerrit,bootstraponline-archive/gerrit-mirror,Distrotech/gerrit,joshuawilson/merrit,MerritCR/merrit,netroby/gerrit,joshuawilson/merrit,jackminicloud/test,pkdevbox/gerrit,qtproject/qtqa-gerrit,renchaorevee/gerrit,ckamm/gerrit,thinkernel/gerrit