services/security/roled/internal: Allow imports from other roles

This change makes it possible to share member sets between roles, which
should make managing the member sets a lot easier.

The config now has a ImportMembers files that contains the names of the
other roles to import from. Example:

role1.conf:
  Members = [ A, B, C ]

role2.conf:
  ImportMembers = [ role1 ]

Then role2's members are A, B, C.

Change-Id: Ibcad056f2735d5071cecb454639cde0aca5664c8
5 files changed