[Building Sakai] Site role change events

[Steven Githens]

Hi Dev,

I'm working on some code to sync the roles of users in Sites with 
corresponding courses that exist in an external cloud service.  In this 
case it's the plagiarism checking service Turnitin.  Whenever someone's 
role changes in Sakai, I need to try and adjust it on Turnitin's 
servers, or if it can't be done right away (maybe because of network 
issues or something) put it in a table to queue up the site id that 
needs to be updated.  Along with a locking table, a quartz job will sit 
there and keep trying the updates.

I'm trying to figure out which event(s) I need to listen for in my Event 
Observer.  Right now I think just "site.upd.site.mbrshp", but I want to 
double check and make sure there aren't some other services/modules that 
might update users roles in sites under a different event code.

At the moment, I don't actually need to listen for if users have been 
removed or added, just if they've been changed in the site.

Cheers,
Steve