added checking bus-access rules

added checking bus-access rules

Implemented enforcing access/opening dbus rules. Added a check to dbuspolicy1_init method
(dbuspolicy1_init will fail if the application is not allowed to access chosen dbus bus).
Moved opening kbus after the check to avoid situation when a process that isn't allowed to
access the bus will hold an open kbus descriptor. No changes are required in glib and dbus
libraries to work properly with the new behaviour of dbuspolicy1_init, but some reordering
should be made to assure that the attempt to access bus will fail exactly in the same place
as when using dbus-daemon.

Refactored logging items (more refactoring of tslog needed).
More compact decision logging for better logs readability. Fixed incorrect logging of checking own policy.
Refactored updating groups to facilitate mocking and testing.
Addedd access/open bus tests. Removed repetitions from Makefile.
Fixed static_assert error msg.

Change-Id: I5042ba50b21ec6cc2c6423b3ade1e5c78d45625b