Add Java 9 Module System Support

[atetzner]

Currently using milton in a project, that uses the Java 9 module system with module-path instead of class-path, is not possible due to the split package problem:

• milton-server-ce depends on commons-beanutils:1.8.2 which is not compatible with the module system due to split-package problem
• milton-server-ce depends on milton-api. Both contain packages with the same name, e.g. io.milton.http.

Please add support for the Java 9 module system by adding module information and define clear exports for packages.