Release 1.1

From release.nix, changes since 1.0:

{
  version = 581;
  changes = ''
    Fix `lorri shell` for zsh. ZDOTDIR is loaded correctly.
  '';
}
{
  version = 572;
  changes = ''
    `lorri daemon` got a `--extra-nix-options` flag to pass further options
    to nix as a JSON object, or at least a subset.
    `builders` and `substituters` is supported for now.
  '';
}
{
  version = 568;
  changes = ''
    Added the `$IN_LORRI_SHELL` environment variable to allow
    differentiation between `nix-shell` and `lorri shell`. The variable is
    set to the path of the currently-evaluated shell file.
  '';
}
{
  version = 534;
  changes = ''
    Rename `lorri internal` commands for consistency:
      - `start_user_shell` -> `start-user-shell`
      - `stream_events` -> `stream-events`
  '';
}
{
  version = 518;
  changes = ''
    Internal subcommands is now visible for all users inside the internal
    subcommand. Example `lorri internal stream_events` instead of `lorri internal__stream_events`.
  '';
}
{
  version = 517;
  changes = ''
    - Fix issue with spaces in PATH entries
  '';
}
{
  version = 510;
  changes = ''
    - The shell.nix template used by `lorri init` was changed to take
      `pkgs` as an argument with import of `<nixpkgs>` used as the
      default value.
  '';
}