* rename export policies to make it direction independent
* split creating neighborsets and prefixsets from applying export policy
* add bgp import policy to deny service VIPs
* add tests for addition of import policy
* update metrics docs & dashboard
* renamed `namespace` label to `svc_namespace` for service metrics as it would be overwritten by most Prometheus setups
* Made histograms for all the controller sync times for better visualization
* added `controller_routes_sync_time`, `controller_bgp_advertisements_sent` & `controller_policy_chains_sync_time` metrics
When the number of nodes in a cluster is high enough, the
`disableSourceDestinationCheck()` logic creates a high number
of requests to EC2, resulting in throttling and subsequent
problems, such as the inability to attach EBS volumes. This is
not necessarily mitigated by the `ec2IamAuthorized` attribute
which was added to overcome this issue, as the number of
requests can still be high enough to reach Amazon's request
limits. In addition, it is not necessary to run this multiple
times in a loop for all the nodes in a cluster, as it is
sufficient to set it once when an instance boots.
This CLI option allows an administrator to turn off this
feature for kube-router so they can use some other means of
setting the attribute.
* Introduced new cmdline flag --bgp-port, which controls BGP Server listening port and remote port of in-cluster node peers
* Introduced new cmdline flag --peer-router-ports, which controls remote BGP port for external peers
* Introduced new node annotation kube-router.io/peer.ports with same effect as --peer-router-ports
