[SUREFIRE-946] fix crash-detection for reuseForks=true, now including hard crashes.

* use a callback to close the TestProvidingInputStream after the forked process ended but before waiting on InputFeeder to finish
* removed the shutdown hook in the forked VM again, removed BOOTERCODE_CRASH (also fixes the other ITs that broke before)
* extend CrashDetectionIT for testing hard VM crashes
* add IT for killed main process with reusable fork