1. Add tagged VLAN to struct vlan_description
(compile limited number of tagged VLANs per description)
For k tagged VLANs, the first k entries in vlan_description.tagged
are used. They are sorted in ascending order. All other entries are
zero. This way os_memcmp() can find identical configurations.
2. Let tagged VLANs be parsed from RADIUS Access-Accept
3. Print VLAN %d+ with %d=untagged VID if tagged VLANs are set
4. Select an unused vlan_id > 4096 for new tagged VLAN configurations
5. Add EGRESS_VLAN RADIUS attribute parsing also for untagged VLANs
Signed-off-by: Michael Braun <michael-dev@fami-braun.de>