create release files to make packaging possible

[CvH]

Hi, due missing release files packaging is not possible anymore since vital packages are now in submodules.

I am not aware that there are "release" files somewhere that includes that submodules ?
Github does not allow downloading with submodules so you have to git clone it your self what is a nogo for packaging.

A working solution would be creating a release at github and upload "proper" release files files to them.
So it would still works just using github.