Write unit tests

Going to write unit test 'program'. This will start with unit testing all public functions in misc.c I may extend to also test all public functions in common.c and there may be 'other' ancillory functions which should also unit test. The program will be stand alone, BUT will be incorporated into makefile.in and makefile.legacy. I will put the source into './src/unused', since it really is unused code (not part of JtR). The tests will also be added to the CI, and likely be a simple build/run test using ASAN, so that buffer over/underflows will be caught.

I am pretty well along on the misc.c unit tests. I will get the unit test project into a PR soon, along with an updated misc.c with numerous issues corrected.

This will be in jumbo-2, but we can easily continue adding more functions into the unit-tests even after J2 is released.