Publish to Sonatype Nexus (Maven Central)

[Lipen]

We need to consider publishing the library (including the native shared libs of the SAT solvers and their JNI counterparts) to Sonatype Nexus ("Maven Central") repository. There is a Gradle plugin to support doing it.

Actually, I've already started implementing it in a separate branch (feature/publish-nexus), but there is still a work to be done around the native artifacts.