[evlatests] Delivery of documents from Executor to Idcaf

[Barry Clark]

Executor sends messages, in the form of XML documents, to Idaf via a
multicast socket, to convey metadata to Idcaf.  Documents bear a sequence
number, which Idcaf checks and records if they are not sequential.

I examined a week's worth of logs looking at Idcaf's sequence number 
check messages.  This looks like about 40,000 documents, mostly informing
Idcaf about the proper Tcal values.

I found 109 instances in which documents were delivered out of the order
in which they were sent (unimportant), including two cases in which the
tardy documents arrived after two later ones.

There is one extraordinary case in which Idcaf claims the document arrived
twice.
54443.idcaf.log:ERROR: Sequence number jump from 36038 to 36038 , mon point = idcaf_tcal_seq.

Overall, the path looks pretty reliable.