calendar-server: activate evolution-source-registry manually at startup

g_dbus_proxy_new() (and library calls that wrap it) has an hardcoded
timeout of 25 seconds, which is insufficient for starting up e-s-r
in certain setups. Avoid a timeout error by starting the service
manually with a longer timeout before hand.
Also demote the error to a warning + exit failure instead of
a crash, to avoid triggering abrt reports.

https://bugzilla.gnome.org/show_bug.cgi?id=735308
Calendar: ignore timeouts starting the calendar-server

In certain cases the timeout for starting the calendar helper can
be reached but the calendar helper still loads fine. If so, just
ignore the timeout and wait until we get a notification from
dbus of the successful start.

https://bugzilla.gnome.org/show_bug.cgi?id=735308