tools: remove systemd xenstore socket definitions

tools: remove systemd xenstore socket definitions

On a system with systemd the xenstore sockets are created via systemd.
Remove the related configuration files in order to be able to decide
at runtime whether the sockets should be created or not. This will
enable Xen to start xenstore either via a daemon or via a stub domain.

As the xenstore domain start program will exit after it has done its
job prepare the same behaviour to be tolerated by systemd for the
xenstore daemon by specifying the appropriate flags in the service
file.

A rerun of autogen.sh is required.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: David Scott <dave@recoil.org>