This patch adds the required firewall rules to automatically allow ssh
access from the local machine (but only from this machine) to all
Kubernetes notes.

Internal networks have been removed from the concept. Therefore they
should no longer be mentioned in the README.

This patch adds a dummy koolbox command into the koolbox container. This
way one can use the exact same commands with a koolbox prefix inside and
outside of koolbox. This should help to simplify future tooling around
make files as well as instructions regarding using koolbox.

This patch allows to optionally build the koolbox container on install
if it isn't already present on the system. This should make the usage as
part of the uplevel CLI easier.

Terraform leaves timestamp-based tfstate backups in the terraform
directory, which don't need to remain after a destroy. This patch fixes
the problem by adding the remaining files to the cleanup command ran
after `terraform destory`.

With nginx-ingress in place (or any other ingress-controller), this
patch provides the required DNS entires that can be used directly or as
part of a CNAME entry.

This patch adjust the label selectors for the loadbalancer and splits
into the expected ingress and master labels to correspond with the
firewall rules.