add agent properties to object type

Tests Finished in 0.643 seconds
32 tests, 199 assertions, 0 failures, 0 skipped
query actor, object.actor, group member, hide empty structs

updated mgo to support ignoring empty struct when querying
http://blog.labix.org/2013/09/05/mgo-r2013-09-04-released

Test Finished in 0.843 seconds
26 tests, 211 assertions, 0 failures, 0 skipped