common: add mask argument to pick_addresses() to specify what we need

Fixes: #4228

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
ceph-mon: only care about public addr during pick_addresses()

Fixes: #4228

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
ceph-osd: specify which types of addresses to pick

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
ceph-mds: specify which types of addresses to pick

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
ceph-syn: specify which types of addresses to pick

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
Merge pull request #314 from ceph/wip-4228

Reviewed-by: Sage Weil <sage@inktank.com>