aaa: more fixes to sync and usages

More fixes were introcued to sync and usages- especially around
adding an already added group/principal.

Change-Id: I0d6198409b7c3e66054716e1abdfcd06e8dd204d
Signed-off-by: Yair Zaslavsky <yzaslavs@redhat.com>
aaa: Using collection instead of list

Change-Id: I5aec7cc3de308e5be3601b87c0543267fa5c018d
Topic: AAA
Signed-off-by: Yair Zaslavsky <yzaslavs@redhat.com>
aaa: Optimizing fetchPrincipalIdsRecursively

The following optimization is introruced:
a. Not using recursive groups resolving - performing manual recursion instead
b. During the manual recrusion - don't fetch groups that were already fetched

Change-Id: I095bb91810e25d345fcd053cbd51d1d25a4b494d
Signed-off-by: Yair Zaslavsky <yzaslavs@redhat.com>