Add support to use libecl in Java using JavaCPP

Hello,
I just wanted to let you know that I started to create all infrastructure to allow to use libecl in Java using [JavaCPP](https://github.com/bytedeco/javacpp).

The idea is to follow the instructions in [JavaCPP Presets](https://github.com/bytedeco/javacpp-presets) and add libecl as another library available among the presets.

Here is the PR I'm working on: https://github.com/bytedeco/javacpp-presets/pull/947
I'm not a C/C++ expert, so I might need some help if someone is interested.

I would like to help to allow to use libecl in Java.

Thanks in advance!