Move to Java's module system

[spoto]

Is there any interest in modifying the code so that it becomes a Java module? Currently, its only dependency is gson, which is already a Java module. Therefore, the transformation should be easy.
I can volunteer this transformation in the next months if it is of interest. It would require to bump the compiler version to Java 9 though (currently, it is fixed to Java 1.6 in pom.xml).

[bowbahdoe]

@spoto I'd like it if you did that, though i have no particular pull here. I think you can use a multi-release jar (maybe with moditect) to keep Java 6 compatibility while adding the module-info.

[WasabiThumb]

Noting, as this project seems unmaintained, that this is implemented in JToml with use of jtoml-all.