New feature: es-result-mode

These changes breaks compatibility.

I am not sure if you agree on this, but I removed the dependency to `curl` completely. It is no longer possible to write the curl command in the beginning if you want to use the `es-query-region`-command.  The problem I am having with it though is that now the only way to query elasticsearch is through emacs.

We have some options to this problem. We can either build some support for specifying the url of the elasticsearch endpoint. We can go back to the `curl` based method and parse the curl command. The last idea I had was that we put the first line inside a comment and we parse that comment. The problem however is that the comment needs to be inside the first `{}`. I think that looks ugly. I am personally partial to building support to inside emacs to ask for url and request method.

If you want to use the query with curl right now, you will need to take the `tail -n+2` of the file. 


PS. I haven't updated the README yet as I wanted to hear what you thought about the problem of how we send the query.