Extend security_DbusMap to grok dbus permissions and what is reachable per-user

Change-Id: If4e1532741e5dc5f094d91fc54e47d494ceb3427

BUG=chromium-os:11926
TEST=./run_remote_test.sh --remote=<ip> security_DbusMap

Review URL: http://codereview.chromium.org/6591012
3 files changed