try to upgrade existing packages
echo yes in case any questions pop up
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
update branch Thu Oct  2 02:29:02 CDT 2014
update branch knitr Thu Oct  2 13:02:26 CDT 2014
update branch knitr Thu Oct  2 14:49:45 CDT 2014
update branch knitr Thu Oct  2 19:41:50 CDT 2014
update branch knitr Thu Oct  2 23:52:25 CDT 2014
update branch knitr Fri Oct  3 02:15:17 CDT 2014
update branch knitr Fri Oct  3 12:36:49 CDT 2014