bridge: add support for VLANs

bridge: add support for VLANs

Add operation for requesting VLAN data for AF_BRIDGE and parsing of
IFLA_AF_SPEC for AF_BRIDGE. VLANs are saved in a bitmap.

Also add dumping of vlan info to link list and neigh list.
For example:

$ nl-link-list --details --family=bridge
br1 ether 8e:6e:0e:86:e5:86 master br1 <broadcast,multicast,up,running,lowerup>
    mtu 1500 txqlen 0 weight 0 index 18
    mode default carrier down
    bridge: pvid 1   all vlans: 1 301-400 601-610   untagged vlans: 1
bond1 ether 46:ef:e1:c9:46:fe <broadcast,multicast,master>
    mtu 1500 txqlen 0 weight 0 index 20
    state down mode default carrier down
    bridge:

Signed-off-by: Wilson Kok <wkok@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
[thaller@redhat.com: modified original patch to use ao_parse_af_full().
  Also renaming new API and drop some #defines]
Signed-off-by: Thomas Haller <thaller@redhat.com>