test-webservice: Avoid leaking mock-sshd processes

With Linux PR_SET_PDEATHSIG, if the test program dies, that will
automatically terminate the child.  To make this work, we also need to
tell GLib not to double-fork, so it remains our child and not pid 1's.

Closes #163

Signed-off-by: Stef Walter <stefw@redhat.com>
test: Increase timeouts on tests that regularly fall over

Closes #166.

Signed-off-by: Marius Vollmer <mvollmer@redhat.com>
Sessions: Work around logind bug re KillUser.

See https://bugs.freedesktop.org/show_bug.cgi?id=71092
Tests: Remove bogus check in check-session.

Must be some refactoring stain that magically managed to not cause the
test to fail.
Tests: Improve README.

The instructions where a bit out of date.

Closes #165

Signed-off-by: Stef Walter <stefw@redhat.com>
Use libgssh for ssh

The "sshpass" program is a useful crutch for some situations, but
ultimately we're going to need a lot more interactive, fine grained
control over ssh.  For example, being able to choose different
authentication types, inspecting host keys, etc.

Additionally, libgssh makes it easy to use the powerful ssh "channel"
feature, which would allow us to do things like spawn a pty+shell on a
separate subchannel, without reauthenticating.