This commit ensures that we have backing support for region IDs up
to and including NTFIP (TABDIMS(5), REGDIMS(1)). The existing setup
would fail (segmentation violation) in the case of a summary vector
of the form
ROFT
36 31 /
/
when the maximum FIPNUM value was 30. We nevertheless support
maximum FIPNUM values exceeding NTFIP.
We add a new optional parameter to the EclInterRegionFlowMap
constructor. The parameter allows client code to specifiy a
"minimum maximum" region ID that all ranks must support. This value
will be enforced during parallel aggregation.
