Fix zarafa SSO
Merge branch 'master' into scabrero/zarafa-sso

Conflicts:
	main/squid/ChangeLog
	main/users/ChangeLog
	main/zarafa/ChangeLog
Merge branch 'master' into scabrero/zarafa-sso

Conflicts:
	main/squid/ChangeLog
	main/users/ChangeLog
fixed merge
create new principals when upgrading
force depend on users 3.0.18
Merge pull request #324 from Zentyal/scabrero/zarafa-sso

Scabrero/zarafa sso