tests: add new torture test for timer infrastructure

This is a new test for the timer infrastructure. It basically consists
of adding 2^N timers per step (where N is the number of step) that
expire in (random() % 10) + 1 seconds. Moreover, we randomly delete
timers that fulfill (random() % 100) < 10 everytime one timer expires.

The default number of steps is 16, the test also allows to check for
timer imprecisions (currently, defaulting to 10ms as aceptable).

The list-based implementation crashes or it seems loop forever with
this test (I guess due to some memory corruption).

BTW, this patch contains one cosmetic clean up since we go back to
8-chars per indentations, which seems to be the policy in osmocom.
1 file changed