VRF-Lite adaptation
Add:
* mibs for work with VRF-Lite :  CISCO-BRIDGE-DOMAIN-MIB and CISCO-CONTEXT-MAPPING-MIB 
* Discovery cisco-vrf-lite for search all [context - intance - vrf lite] from cisco
* Discovery route for get all ip tables from cisco(ospf, bgp, direct...)

Modification in discovery:
* arp-table to work with vrf-lite context (sql changes and foreach for search with the device context array)
* bgp-peers for work with vrf-lite context (sql changes and foreach for search with the device context array)
* function for work with vrf-lite  (sql changes and foreach for search with the device context array)
* ipv4-addresses  for work with vrf-lite  (sql changes and foreach for search with the device context array)
* ipv6-addresses  for work with vrf-lite  (sql changes and foreach for search with the device context array)

Modification in polling
* bgp-peers change for work with vrf-lite context and change to librenms logic (no more `` for execute the code, the code now the librenms function for this) and serveral logic fix 
* ospf change for work with vrf-lite context and change to librenms logic and serveral logic fix

Other modification 
* snmp add to the explote 2 of the the snmp_get_multi function, this is more generic and work with all kind of logic (with and without context) 
* snmp add context if SNMP v3 and if the device have the key context_name (very importat!! for work with vrf-lite context)
* poller add the vrf-lite array to the device
* default add discovery modulte to the $config array
* Other changes...
Visual VRF-Lite adaptation

Add global view:
* route see all the table ip get by the discovery module route

Changes global view
* routing  add to the view the route 
* bgp get the bpg with or without context and print special  intance:vrf if exist the vrf-lite
* ospf get the ospf with or without context and print special  intance:vrf if exist the vrf-lite

Add device view
* route see all the table ip get by the discovery module route but only for the device selected

Changes device view
* Add the option to see only the information from one vrf (this include all the values vrf context dependent)
* Other visual modification for see the information (like the tables)