Add infrastructure to integrate the DTrace test suite with Kyua.

Add infrastructure to integrate the DTrace test suite with Kyua.

For each test category, we generate a script containing ATF test cases for
the tests under that category. Each test case simply runs dtest.pl (the
upstream test harness) with the corresponding test files. The exclude.sh
script is used to record info about tests which should be skipped or are
expected to fail; it is used to generate atf_skip and atf_expect_fail calls.
The genmakefiles.sh script can be used to regenerate the test makefiles when
new tests are brought it from upstream.

The test suite is currently not connected to the build as there is a small
number of lingering test issues which still need to be worked out. In the
meantime however, the test suite can be easily built and installed
manually from cddl/usr.sbin/dtrace/tests.

Reviewed by:	ngie
Sponsored by:	EMC / Isilon Storage Division