remove the names of pkgs_old
remove pkgs_old from apt-get **after** the recipes have been installed, e.g. fftw is an old package, but we should install libfftw3-dev anyway
force apt-get if failed
only install the R packages that are not loadable
add libgeos-dev for rgdal
for apt-get build-dep, remove the packages that have known dependencies from the list