nixos-generate-config: Don't generate /var/lib/nfs/rpc_pipefs filesystem

It's automatically mounted if the system has support for NFS.
nixos-generate-config: Don't generate filesystem options

We don't want to hardcode configuration options that the current kernel chose
for us when mounting the filesystem, since the defaults can change in the
future.
Re-introduce mkStrict function in stable branch, as some packages might still be dependent on it (e.g. nixops). Added a warning that the function is obsolete.
Fix EC2 creation script for latest nixops
Revert "nvidia: Update to version 331.20"

This reverts commit 42a2b9333698044f8c4f8aa146651698d8f44c80.  It
causes Firefox to crash.
Revert "Cache::Memory: Disable tests"

This reverts commit 2448d65cc9d7b1847d7ecda28b3445e3d883078d.

Applied to the wrong branch...
mkStrict used mkOverride 0 before.
Revert "new systemd can't inhibit lid switches"

This reverts commit f9fb7b7457e636f4f7edff866cee1c1812aa9501.
Cf. https://github.com/jcumming/nixos/commit/da2c160471f73af

(cherry picked from commit 8e0d77632e02720a8adf8126f126990501299191)

Conflicts (take master):
	nixos/modules/services/x11/display-managers/default.nix
Added expression to build ATS/Anairiats from its source
distribution. This should be sufficient for building
ATS/Postiats from source, including bootstrapping.