A Docker image for Kibana designed to work with Kubernetes logging

This pull request contains the source for a special Kibana Docker image which is set up to work with Elasticsearch and Kibana in separate pods or in the same pod. 
I think using single quotes is more clear than the backslashes.

Optionally, you can also use this syntax for default values (which will not repeat the variable name):

```shell
: ${VARNAME:=default_value}
```

In this case:

```shell
: ${ES_HOST:='"+window.location.hostname+"'}
: ${ES_PORT:=5601}
```