[I2rs-proto-dt] couple YANG details

[Andy Bierman <[e-mail]>]

Hi,

I would like to simplify the draft a bit further.

1) module-level "ephemeral" flag
Since the data node flag applies to the entire subtree,
it should be simple enough to just require each top-level
data node to declare 'ephemeral true' if needed.
There are usually 1 - 2 top-level data nodes per module so
this is not a burden.  Checking 2 places is too complicated
and they can conflict.

2) groupings wrt/ edit overlap

YANG already has a way to say what sub-nodes must
be present (mandatory=true, min-elements>0).
Is this good enough for I2RS?  Can the requirements
for the ephemeral version be different than the
persistent version, wrt/ mandatory & min-elements?