Deprecate setting operating system limits from named.conf
It was possible to set operating system limits (RLIMIT_DATA, RLIMIT_STACK, RLIMIT_CORE and RLIMIT_NOFILE) from named.conf. It's better to leave these untouched as setting these is responsibility of the operating system and/or supervisor.
Deprecate the configuration options and remove them in future BIND 9 release.
(cherry picked from commit 379929e0)
Closes #3676 (closed)