desktop: move terminalrc to new path
desktop: remove wheezy testing code
desktop: don't overwrite pam common-auth and login

In b682f5, a naive me thought to remove pam_authdelay by removing the
line from two pam settings files and puppeting the entire giant files.

As Dara points out, this is what actually broke pam-auth-update (in
addition to being messy). It was only intended to work around a
persistent lightdm freezing bug, which is (hopefully) no longer an
issue. So, we can remove these files.

(If we decide to disable pam_authdelay again later -- which isn't really
a bad idea on the desktops -- we should do it not like this.)
Revert "desktop/grub: fix unrestricted boot on wheezy"

Reverting this change in the jessie branch, since it won't be needed
after merge (and we're already similarly removing other version
detection cruft).
desktop/packages: remove gftp-gtk (not in jessie)

Looks like gftp-gtk didn't make it into jessie due to a bug:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=763314

It's fixed now, but seems it won't be in jessie.
desktop: install xscreensaver before disabling it

This might seem silly, but we use it for its locking capabilities, so it
actually does make sense to install and then disable (i.e. change to
blanking mode only).
Merge branch 'jessie-desktops'