Fix automatic mouse grabbing/releasing when running as a vmware guest.
1. The xf86inputvmmouse is not loaded by default. Add it.
2. InptutDevice sections for which specify a driver are ignored if
AutoAddDevices is enabled (which it is by default). See [1]. Instead use
an InputClass to load the vmmouse driver.
[1] https://www.x.org/archive/X11R7.7/doc/man/man5/xorg.conf.5.xhtml#heading8
It was lacking the dbus configuration to bind to
org.freedesktop.DisplayManager, and it was passing fixed TTY/display
numbers to the X server (see 9be012f0d4).
Using the example before this commit resulted in the following error:
```
error: value is a string while a list was expected, at /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/services/misc/nix-daemon.nix:349:37
```
* Sync systemd units with upstream. Upstream uses SIGUSR2 instead of SIGHUP
to reload the clamd service.
* Convert freshclam service to a oneshot service activated by a systemd timer.
This way we can make clamd wait for freshclam to finish fetching the virus
database before failing to start if the database doesn't exist yet.
* Fixes console tools to work as expected as they require hardcoded config
file locations.
The old etcd port 4001 is no longer enabled by default in etcd 3.
The new port is 2379 and is officially assigned by IANA.
There were still some services left that expect etcd on port 4001 by default.
This changes the default to 2379 everywhere.
It should not cause problems for users as the etcd by nix does listen on the new port only by default anyway.
This needs to be included for VirtualBox to detect that it needs to start the video driver. "modesetting" is also set in virtualbox-image.nix but this line seems to take precedence over that one (even though the virtualbox-image.nix has a higher override?) This should fix the problems that I and a few others have been having with the .ova files built for nixos.org.
Fixes #20007.
