Fix abort and SIGSEGV child signal handling and add copyright text.

The initial test framework commit (tagged test-p0) did not properly
handle SIGABRT or SIGSEGV (or other) signals from the forked child
process. Alarm, SIGABRT and all other signals are now properly handled
by the parent process, and are currently considered failures.
Additionally:

- Fix increment of run and failed variables triggered by SIGALRM
  signals.
- Change failed test to passing test
- Reorganize header and implementation code
- Add license and copyright details