[sakai2-tcc] Regresssion found in Site Info's Add Participants with Sakai 2.7.0

[Jean-Francois Leveque]

Hi all,

With Sakai 2.6, you could resubmit a complete updated list of users and 
it was able to only add the new ones.

With 2.7.0, we get:
"The following participants are already members of this site and can not 
be re-added:"
and cannot get through without removing the users that are already there.

With large lists, this is real pain for our users.

Don't know about any option to get this back to 2.6 behavior, I think 
this is a regression.

WDYT?

Cheers,

J-F