Fixed #15. No longer update 'last accessed' and use guestStatus in collabPersonHash

Note that this should make sure that all collabPersonHashes are invalidated but after that are only updated once a SAML attribute changes.
Merge branch 'bugfix/15-ldap-performance'

* bugfix/15-ldap-performance:
  Fixed #15. No longer update 'last accessed' and use guestStatus in collabPersonHash

Conflicts:
	library/EngineBlock/UserDirectory.php