LibreNMS vrf-lite

New pull request with only 2 commit

Changes made:
* VRF-lite compatible
* Ipv4 SNMPv3 context compatible (VRF-Lite)
* Ipv6 SNMPv3 context compatible (VRF-Lite) (only DB and discovery/poller, not in the html view)
* Bgp SNMPv3 context compatible (VRF-Lite)
* OSPF SNMPv3 context compatible (VRF-Lite)
* HTML VRF-lite compatible (reference made by ipv4* tables)
* Disocovery route module
* HTML visual changes
* Add some MIBs
* Other global changes