MFC 272159,272161,272386,272446,272547,272548,273210:

MFC 272159,272161,272386,272446,272547,272548,273210:

- Make lagg protos a enum.

- When reconfiguring protocol on a lagg, first set it to LAGG_PROTO_NONE,
  then drop lock, run the attach routines, and then set it to specific
  proto. This removes tons of WITNESS warnings.

- Make lagg protocol attach handlers not failing and allocate memory
  with M_WAITOK.

- Virtualize lagg(4) cloner.  This change fixes a panic when tearing down
  if_lagg(4) interfaces which were cloned in a vnet jail.

  Sysctl nodes which are dynamically generated for each cloned interface
  (net.link.lagg.N.*) have been removed, and use_flowid and flowid_shift
  ifconfig(8) parameters have been added instead.  Flags and per-interface
  statistics counters are displayed in "ifconfig -v".

- Separate option handling from SIOC[SG]LAGG to SIOC[SG]LAGGOPTS for
  backward compatibility with old ifconfig(8).

- Move L2 addr configuration for the primary port to a taskqueue.  This fixes
  LOR of softc rmlock in iflladdr_event handlers.

- Call if_delmulti_ifma() after LACP_UNLOCK().  This fixes another LOR.

- Fix a panic in lacp_transit_expire().

- Fix a panic in lagg_input() upon shutting down a port.

- Use printb() for boolean flags in ro_opts and actor_state for LACP.

- Fix lladdr configuration which could prevent LACP mode from working.

- Fix LORs when a laggport interface has an IPv6 LLA.

git-svn-id: svn://svn.freebsd.org/base/stable/10@287723 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f