Check process only dies when last process descriptor closed.
Comment out failing wildcard waitpid() test
Add collection of directory operation tests.

Adapted from new content in FreeBSD 10.0 file
tools/regression/security/cap_test/cap_test_capabilities.c

Also restore build on FreeBSD 9.x.
Add test for pdfork()ed child being terminated on parent exit.

A neat side effect of pdfork() semantics is that when the parent
exits, the process descriptor is closed, which terminates the
child.

This does not apply if the PD_DAEMON flag was set on pdfork() though.