MFC r293621,r293622,r293815:

r293621:

• Delete non-TAP testcases
• Add a conf.sh file for executing common functions with geom_gate
• Use attach_md for attaching md(4) devices
• Don't hardcode /tmp for temporary files, which violates the kyua sandbox
• Add/increase sleeps to try and improve synchronization
• Add debug output for when checksums fail

test-1.t:

• Use pkill for killing ggated

r293622:

Remove Makefile now that the testcases are all TAP based and
prove -rv can be used on them

r293815:

Add conf.sh file missed in r293621