[evlatests] Subarrays

[Barry Clark]

While I'm thinking of it, a couple of additional notes.

When there is subarray2 running, and a script is started in subarray1,
there are two (ten second) integrations produced in subarray2 which are
garbage, but are not flagged bad.

When a script is killed, and the other subarray continues running, 
unflagged data continues to be produced for the dead subarray (it will 
eventually become nonsense when the linear extrapolations it is coasting 
on become untenable).