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.
Merge pull request #1791 from wizeman/u/nixos-gen

nixos-generate-config: improve filesystem generation
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 Added a warning that the function is obsolete.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.