SAML session purge
Portal script purgeCentralCache has a slight design bug :
it purges SAML sessions, if samlStorage is defined in config and if it is different from globalStorage (and if it is not "Apache::Session::Memcached", but this out of scope). However, samlStorage and globalStorage may be equal, but storage options may differ : in that case, SAML sessions would not be purged.
To fix that bug, we could compare storage options in addition to storage module. But comparing hash ref may be boring, and it would be easier to consider that if samlStorage or samlStorageOptions are defined, then SAML data storage differs from session storage (since by default SAML data are stored with sessions). Right ?