Merge pull request #5451 from opensourcerouting/rcu-log

logging subsystem rewrite

diff --cc bfdd/bfdd.c
Simple merge

diff --cc bgpd/rfapi/rfapi_vty.c
Simple merge

diff --cc configure.ac
Simple merge

diff --cc ldpd/ldpd.c
Simple merge

diff --cc lib/grammar_sandbox_main.c
Simple merge

diff --cc lib/libfrr.c
Simple merge

diff --cc tests/bgpd/test_peer_attr.c
Simple merge

diff --cc tests/lib/cli/common_cli.c
Simple merge

diff --cc tests/lib/northbound/test_oper_data.c
Simple merge

diff --cc vtysh/vtysh.c
Simple merge