client: Setup also XDG_RUNTIME_DIR under /run/user/<uid> for files
that do not need to be persisted across reboots. Keeps user home
directory cleaner.
client: Fix check for sambahomes tag in puavo-ltsp-init-nfs
client: puavo-ltsp-init-nfs now mounts by default /home as one mount
and uses individual user home mounts over CIFS is sambahomes tag
is set.