bgpd, zebra: Use next hop tracking for connected routes too

Allow next hop tracking to work with connected routes
And cleanup obsolete code in bgp_scan and bgp_import.

Signed-off-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Edits: Paul Jakma <paul.jakma@hpe.com> Rebase re-ordering conflicts with
       NHT route-map, potential errors.
15 files changed