Support multi-tenancy with Spring Security for roles and permissions

[dogeared]

The challenge here is that all href references that are used in hasRole need to be resolved at startup time.

The implementation needs to be discussed further, but one approach would be to have Groups named the same across Organizations.

A solution then would be to:

1. get the Organization that the logged in user belongs to
2. get the named Group from that Organization (which would actually belong to the Directories mapped to the Organization)
3. confirm that the logged in user belongs to the named Group