Calendar: assign thcipriani to train as default

Currently when the train isn't assigned (or the train task isn't ready)
the whole calendar fails to generate for the week.

Instead, this change generates some calendar.

In the case where the train isn't assigned, it flags thcipriani as
primary and secondary.

In the rarer case where the train task hasn't been created it uses
0.00-0.wmf-0 as the train version and flags thcipriani as primary and
secondary.