Integrate usr.bin/sed testcases

- Convert sed regress testcases over to ATF
- Install multitest.t.

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
Nuke this file because it's no longer used

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
Nuke because all integrated tests are handled now

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
Handle the FREEFORM case and cleanup the script

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
*sort* of integrate this in

This test is broken and I need to determine why..

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>