`nix-store --delete'. But unprivileged users are not allowed to
ignore liveness.
* `nix-store --delete --ignore-liveness': ignore the runtime roots as
well.
* Added `build-users-group', the group under which builds are to be
performed.
* Check that /nix/store has 1775 permission and is owner by the
build-users-group.
* Some refactoring: put the NAR archive integer/string serialisation
code in a separate file so it can be reused by the worker protocol
implementation.
containing functions that operate on the Nix store. One
implementation is LocalStore, which operates on the Nix store
directly. The next step, to enable secure multi-user Nix, is to
create a different implementation RemoteStore that talks to a
privileged daemon process that uses LocalStore to perform the actual
operations.