Fuzzing triggers many assertion failures, which generates enormous log output. AFAIK, there is no way to make `NSAssertionHandler` _not_ write to log, and the assertions themselves are valid. Thus, implement a workaround: only output the last part of the logs in Travis, in order to avoid exceeding the log size limit (4 Mb).
* Added fuzzing script to run all fuzzing targets on cron jobs.
* Added travis fuzzing script and `FUZZING_DURATION` to control fuzzing time.
* Given a total fuzzing duration, select 1 target to run for half of
the duration, and divide the remaining duration over the rest of
targets equally.
Konstantin Varlamov