controller: Send ARP/ND for stale mac_bindings entries. #3458

Job	Run time
Prepare container	1m 1s
osx clang --disable-ssl	2m 14s
linux rpm fedora	7m 2s
linux gcc --disable-ssl	2m 37s
linux clang --disable-ssl	2m 41s
linux gcc test -300	9m 59s
linux gcc test 301-600	7m 49s
linux gcc test 601- unstable	7m 45s
linux clang test sanitizers -300	13m 7s
linux clang test sanitizers 301-600	10m 16s
linux clang test sanitizers 601- unstable	12m 26s
linux gcc test -ljemalloc -300	10m 30s
linux gcc test -ljemalloc 301-600	7m 56s
linux gcc test -ljemalloc 601- unstable	7m 50s
linux gcc system-test-dpdk dpdk -100	16m 51s
linux gcc system-test-dpdk dpdk 101- unstable	19m 3s
linux gcc system-test-userspace -100	16m 11s
linux gcc system-test-userspace 101- unstable	16m 48s
linux gcc system-test -100	20m 32s
linux gcc system-test 101- unstable	25m 46s
linux clang system-test sanitizers -100	22m 39s
linux clang system-test sanitizers 101- unstable	28m 15s
linux x86 gcc --disable-ssl	2m 42s
	4h 32m 0s

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