Refs #16606 NFPs get access to participants and subscribers listings

Refs #16774 all participants are now either signups or subscribers
Refs #16769 update view permission for OBSERVER and WAITING roles
Refs #16795 observers should have access to the list or participants

git-svn-id: https://svn.eionet.europa.eu/repositories/Naaya/trunk/eggs@20394 a0171fae-0946-0410-966d-b1775066cd26