FENNEL (exec): tracing stream execution prints tuples only when TRACE_FINER.  (Was quite verbose before with unit tests. Under farrago, trace-level can be fine-tuned  for each XO, but not with C++ unit tests.)
FENNEL (exec): tracing stream execution prints tuples only when TRACE_FINER.
 (Was quite verbose before with unit tests. Under farrago, trace-level can be fine-tuned
 for each XO, but not with C++ unit tests.)

[git-p4: depot-paths = "//open/dt/dev/": change = 3238]

LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb