Recursive extraction of GRID links

This is causing the failure in !256 (merged).

It seems that the scripts are for some reason not using enough steps to resolve

950xxx/950031/mc_13TeV.Sh_228_ttbar_AllHadronic_EnhMaxHTavrgTopPT.GRID.tar.gz -> ../../700xxx/700050/mc_13TeV.Sh_228_ttbar_AllHadronic_EnhMaxHTavrgTopPT.GRID.tar.gz

back to

/eos/user/c/cgutscho/mc/700047/mc_13TeV.Sh_228_ttbar_AllHadronic_EnhMaxHTavrgTopPT.GRID.tar.gz

By the way @cgutscho @fsiegert isn't this workflow problematic? You have multiple files pointing to /eos/user/c/cgutscho/mc/700047/mc_13TeV.Sh_228_ttbar_AllHadronic_EnhMaxHTavrgTopPT.GRID.tar.gz, which has already been transferred to cvmfs, so in principle Chris can decide to remove this file from his eos area and CI again would fail.