Upgrade script to handle policykit -> polkit migration.
Upgrade script to handle policykit -> polkit migration.

This script also helps out with chromeos-u-boot-next -> chromeos-u-boot
migration.

BUG=chromium-os:16310
TEST=Run the script and verify right packages are uninstalled.

Change-Id: I4ebaa0a0b3e1eea32005b4d2a47f4581e44d825c
Reviewed-on: http://gerrit.chromium.org/gerrit/2309
Tested-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>

vmware/coreos-scripts,crawford/scripts,crawford/scripts,mischief/scripts,vmware/coreos-scripts,fivethreeo/scripts,BugRoger/scripts,crawford/scripts,smilart/scripts,fivethreeo/scripts,bcwaldon/coreos-scripts,endocode/scripts,vmware/coreos-scripts,BugRoger/scripts,marineam/coreos-scripts,marineam/coreos-scripts,coreos/scripts,zhang0137/scripts,gtank/scripts,coreos/scripts,andrejro/coreos--scripts,endocode/scripts,gtank/scripts,endocode/scripts,bcwaldon/coreos-scripts,smilart/scripts,mjg59/scripts,smilart/scripts,nicescale/scripts,mjg59/scripts,sigma/coreos-scripts,zhang0137/scripts,sigma/coreos-scripts,glevand/coreos--scripts,trnubo/scripts,gtank/scripts,trnubo/scripts,nicescale/scripts,zhang0137/scripts,nicescale/scripts,mischief/scripts,trnubo/scripts,bcwaldon/coreos-scripts,mischief/scripts,andrejro/coreos--scripts,sigma/coreos-scripts,glevand/coreos--scripts,mjg59/scripts,BugRoger/scripts,marineam/coreos-scripts,andrejro/coreos--scripts,fivethreeo/scripts