Tests are dividing on error vs working, and DHCPv4 vs DHCPv6.

Names of files about test xyz have xyz as body and an extension.

Extensions:
 - .err4 = source for error test in DHCPv4
 - .errF = source for error test in DHCPv4 with -r fatal
 - .errP = source for error test in DHCPv4 with -r pass
 - .err6 = source for error test in DHCPv6
 - .err  = source for error test in DHCPv4 and DHCPv6
 - .msg  = resultat (first line of standard error) for error test
 - .in4  = source for working test in DHCPv4
 - .in6  = source for working test in DHCPv6
 - .ind  = source for working test in DHCPv4 with -D
 - .inD  = source for working test in DHCPv6 with -D
 - .inn  = source for working test in DHCPv4 with -N
 - .inN  = source for working test in DHCPv6 with -N
 - .inl  = source for working test in DHCPv4 with -l $HOOK
 - .inL  = source for working test in DHCPv6 with -l $HOOK
 - .outl = resultat for working test with default hook library path
 - .outL = resultat for working test with default hook library path
 - .out  = resultat for working test
There is no working test in both DHCPv4 and DHCPv6.
The body of the name of a working test must include 4 or 6 so
the .out can be submitted to kea-dhcp4 or kea-dhcp6

runone.sh xyz.ext
 -> run the xyz test
runall.sh
 -> run all tests

Check output syntax with kea-dhcp4 and kea-dhcp6:
 - Set KEA4 and KEA6 environment variables to kea-dhcp4 and kea-dhcp6
 - Set HOOK to a place to find hooks (currently libdhcp_flex_id.so),
   please use the directory name with a trailing /
 - The en0 interface is supposed to exist (or replace "en0" in all files)
 - Note that runall.sh must be run before checkall.sh

checkone.sh xyz.out
 -> check the syntax of xyz.out
checkall.sh
 -> check the syntax of all .out files