factor out and quiet update.packages()
a (hopefully) final attempt to install packages that were built under R 2.x
avoid installing old packages, and also manually remove them if installed; does this solve the abind problem?!
special treatment for abind and xtable, sigh
put special packages in the front
pick some packages for the `separate` field
put time-consuming pkgs in the back
only BTYD and R.rsp seem to be time-consuming
update branch Thu Oct  2 02:29:06 CDT 2014