cls,msg: Fix use of set_in4_quad() to set a entity_addr_t

Signed-off-by: David Zafman <david.zafman@inktank.com>
Add entity_addr_t to watch_info_t and Watch

Signed-off-by: David Zafman <david.zafman@inktank.com>
osd: Drop watchers from blacklisted clients

On new map (possible blackist change) or populate ObjectContext
   check watcher address against blacklist

fixes: #3527

Signed-off-by: David Zafman <david.zafman@inktank.com>