changed wording to prevent confusion of using R53 in govcloud vs needing to make public facing r53 entries

When it syncs AWS DNS with k8s cluster content (at `--interval`), external-dns submits two distinct Route53 API calls:
* to fetch available zones (eg. for tag based zones discovery, or when zones are created after exernal-dns started),
* to fetch relevant zones' resource records.

Each call taxes the Route53 APIs calls budget (5 API calls per second per AWS account/region hard limit), increasing the probability of being throttled.
Changing synchronization interval would mitigate those calls' impact, but at the cost of keeping stale records for a longer time.

For most practical uses cases, zones list aren't expected to change frequently.
Even less so when external-dns is provided an explicit, static zones set (`--zone-id-filter` rather than `--aws-zone-tags`).

Using a zones list cache halves the number of Route53 read API calls.

The k8s external-dns project now uses the official Kubernetes projects
container registry at k8s.gcr.io. Update all references to use the new
registry.

* Update apiVersions in docs

Update docs to reflect new apiVersions for ingresses and deployments.

* Add selector to apps/v1 deployments

* intial removal of inappropriate terminology
Signed-off-by: Raffaele Di Fazio <raffo@github.com>

* removed other occurrences
Signed-off-by: Raffaele Di Fazio <raffo@github.com>

* gofmt
Signed-off-by: Raffaele Di Fazio <raffo@github.com>

* addresses comment
Signed-off-by: Raffaele Di Fazio <raffo@github.com>

* gofmt
Signed-off-by: Raffaele Di Fazio <raffo@github.com>

Using EC2 Instance Roles to provide Route 53 permissions is overly
permissive and dangerous.  Emphasize using alternatives such
as EKS IAM Roles for Service Accounts, kiam, or kube2iam that
limit access to the ExternalDNS pod.

`Deployment` has been removed from `apiVersion: extensions/v1beta1`

See https://kubernetes.io/blog/2019/07/18/api-deprecations-in-1-16/

The extensions/v1beta1 API is deprecated for Deployment and with 1.16 is
not served by default anymore. This breaks the examples on k8s 1.16.

See this blog post for details on the deprecations:

https://kubernetes.io/blog/2019/07/18/api-deprecations-in-1-16/

Amazon EKS supports IAM Roles for Service Accounts. It mounts tokens
files to `/var/run/secrets/eks.amazonaws.com/serviceaccount/token`.
Unfortunately, external-dns runs as 'nobody' so it cannot access this
file. External DNS is then unable to make any AWS API calls to work:

```
time="2019-09-11T07:31:53Z" level=error msg="WebIdentityErr: unable to read file at /var/run/secrets/eks.amazonaws.com/serviceaccount/token\ncaused by: open /var/run/secrets/eks.amazonaws.com/serviceaccount/token: permission denied"
```

See: https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts-technical-overview.html

Below are the file permissions mounted on External DNS pod:

```
~ $ ls -al /var/run/secrets/eks.amazonaws.com/serviceaccount/
total 0
drwxrwxrwt    3 root     root           100 Sep 11 06:40 .
drwxr-xr-x    3 root     root            28 Sep 11 06:40 ..
drwxr-xr-x    2 root     root            60 Sep 11 06:40 ..2019_09_11_06_40_49.865776187
lrwxrwxrwx    1 root     root            31 Sep 11 06:40 ..data -> ..2019_09_11_06_40_49.865776187
lrwxrwxrwx    1 root     root            12 Sep 11 06:40 token -> ..data/token
~ $ ls -al /var/run/secrets/eks.amazonaws.com/serviceaccount/..data/token
-rw-------    1 root     root          1028 Sep 11 06:40 /var/run/secrets/eks.amazonaws.com/serviceaccount/..data/token
```

This commit fixes this problem by specifying securityContext to make
mounted volumes with 65534 (nobody) group ownership.

Fixes `Failed to watch *v1.Node: unknown (get nodes)`

Tutorial specifies version >0.4 which also removed the requirement for a trailing period.  New users could misunderstand the trailing dot as a significant syntax.  Removing the dot simplifies the configuration of the annotation.

This PR is a comment about "Multiple DNS names per Service" setting.

I got stuck here and opened #865 because I thought it was a bug. I hope this will help others set it up correctly the first time.

This way the use of `jq`, and the output in this document would make sense.

Introducing support for NodePort services might break cluster which
using RBAC

* allow external-dns to list nodes
Signed-off-by: Nick Jüttner <nick@zalando.de>

* Add recent changes to the changelog
* Update version in docs
Signed-off-by: Nick Jüttner <nick@zalando.de>

* Minor changes to docs and faq

* Other minor changes

* better docs

* Addressed comments