Clarify odd print-control usage.

[pp-mo]

re-organised a bit + added comments to make things clearer ...
.. perhaps ?

[pp-mo]

N.B. I also tried removing the call to _formatArray out of the context-manager, i.e. as if the output was entirely determined by the args to formatArray + we only needed to get the 'legacy' arg format right.
But it didn't work, i.e. the low-level _formatArray operation does also rely on the current print options.
Yuck!.