Provide JPMS module name

[sbordet]

Would be great if a stable JPMS module name can be provided, as simply as adding Automatic-Module-Name to the manifest in the jar.

This will allow projects that are moving to proper JPMS modules to reference a stable JPMS name for jnr-unixsocket in their module-info.java.

I would suggest to not use com.github as prefix, but perhaps just org.jnr, but it's ultimately your choice.

Thanks!

[sbordet]

Also, jnr-unisocket has a split package with jnr-enxio: jnr.enxio.channels.

This makes impossible to use jnr-unixsocket as JPMS module, even adding the Automatic-Module-Name entry.

[headius]

Fixed along with #58.