Add jigsaw module information to this library.

[sjoerdtalsma]

No description provided.

[sjoerdtalsma]

Probably going to need:

• https://blog.codefx.org/java/java-module-system-tutorial/
• https://blog.codefx.org/java/five-command-line-options-to-hack-the-java-9-module-system/
• and / or https://blog.codefx.org/java/module-system-optional-dependencies/

[sjoerdtalsma]

note: Experimented with maven-javadoc-plugin version 3.1.0-SNAPSHOT in #106 and found out that javadoc in openjdk 11.0.2 throws errors about the unnamed module, so make sure either the JDK or maven-javadoc-plugin contains the proper fix-versions