[evlatests] idcaf

[Barry Clark]

When I arrived, idcaf was not writing data.  Sequence of events was

Test file for Gustaaf ran to completion.
At that time, there was a tour group in the control room, and array sat
   idle (nothing running in executor).  
After 10+ minutes, Xsysstart was started.  No data was written.
After ~10 minutes, Xsysstart was restarted.  Still no data.
Called Walter.  He restarted idcaf, things came alive.


We should make sure that the vispipe->idcaf path can survive 10 minutes 
of idleness.