client: do not start lightdm when kdumping
Do not allow reboot/shutdown on a guest session on a webkiosk host
(all webkiosk host sessions are guest sessions, but we do an extra
check).  This does not actually prevent users from reboot or
shutting down webkiosk hosts, simply breaks the functionality
from webmenu (whose user interface should be modified regarding this).

This is a quick hack that might be taken away when a more proper
solution is in place.  Perhaps that might include dbus-configuration
change and webmenu interface change.
client: Specify connection timeouts for thin client ssh connections so
that the thin client automatically logs out even if something went wrong
with the connection.
client: Add dependency to ltspfs
Append PUAVO_TAG_* environment variables to /etc/environment
from puavo-configure-client (one environment variable for each tag).
Do append_tags_to_environment() in puavo-configure-client
in a separate function and do some input validation
(not all tags now go in).
Merge branch 'master' into trusty

Conflicts:
	debian.default/control
Add a dependency to ltspfs (should have been part of the merge commit).