Import atf 0.22 snapshot 55c21b2c5fb189bbdfccb2b297bfa89236502542

The main improvement is the ability to skip a test that is expected to
fail.

Import atf 0.22 snapshot ca73d08c3fc1ecffc1f1c97458c31ab82c12bb01

This includes improvements to the atf-sh helper functions that
significantly reduce the number of spawned processes for each test
and therefore speeds up running the testsuite noticeably.

MFV: Import atf-0.21.

Merge ATF 0.16 from vendor/atf/dist.

Provenance: http://code.google.com/p/kyua
Discussed with: gibbs, gnn, keramida, mdf, mlaier,
Discussed with: Garrett Cooper