Add support for running named under `rr record -h`

Currently start.pl has support for running named under valgrind which is mostly useless now because AddressSanitizer is better integrated, but we could benefit from running named under rr chaos mode.

Therefore, I propose to remove the valgrind support from start.pl, and add support for running system tests under rr.

I think it would be more useful to integrate this into conf.sh with more tools than just named.