New Issue: let the module version be free

[Remi Forax]

Currently the module version does not appear in module-info.java is stored as a string in the module-info.class when a modular jar is created.
So the version doesn't appear in the Java source code and is provided by the build tool we love using any format we ask.

At runtime, when the module-info.class is read, the version is parsed using the class ModuleDescriptor.Version that verifies a very specific format [1].

Given that the format will never be the right one, i.e. never support every possible module version formats that exist in the universe,
i propose to not try to parse the version string and to exposes it only as a string at runtime and let the module systems that are built on top of jigsaw to parse the version as they want. 

Rémi

[1] http://download.java.net/java/jigsaw/docs/api/java/lang/module/ModuleDescriptor.Version.html