Add remote and upstream branch on fetch.
Add remote and upstream branch on fetch.

Will add a config option to stop this, but 'gsr clean' already cleans up.

Now the subrepo remote is always available.

stsquared99/git-subrepo,ingydotnet/git-subrepo,stsquared99/git-subrepo,perlpunk/git-subrepo,dzzh/git-subrepo,brijendratiwari/git-subrepo,ingydotnet/git-subrepo,perlpunk/git-subrepo,brijendratiwari/git-subrepo,dzzh/git-subrepo