- rewrite the semop(2) implementation so that it now conforms to the
specification, including atomicity, support for blocking more than
once, range checks, but also basic fairness support;
- fix permissions checking;
- fix missing time adjustments;
- fix off-by-one errors and other bugs;
- do not allocate dynamic memory for GETALL/SETALL;
- add test88, which properly tests the semaphore functionality.