ws: Add a timeout during test-webservice.c tests using alarm()

We may want to expand this further once we get some experience with
how it works.

Closes #577
Reviewed-by: Marius Vollmer <marius.vollmer@redhat.com>
ws: Don't send "ping" commands during test-webservice.c tests

This would previously limit the tests to having to run in
5 seconds or less, or erroneous results would result.

Reviewed-by: Marius Vollmer <marius.vollmer@redhat.com>