Reorganize project structure

[skrah]

After the deprecation of distutils the separate libraries are hard to maintain. To facilitate maintenance and development, the following changes will be made:

Repository renamings

ndtypes ==> libndtypes

xnd ==> libxnd

gumath ==> libgumath

These are of course easily reversible if the new structure does not work out.

New combined repository

The new combined repository will be named xnd and will contain all libraries and Python modules. The Python modules have a dual function: They are built for running the library tests but they are also the authoritative source for the Python packages.

Build system

In order to maximize independence from the Python packaging machinery, xnd will be entirely built by CMake. CMake has excellent support for building Python C-extensions without relying on any third party packages.

The Python modules built by CMake are of course directly usable for testing and development, thereby making support for editable installs unnecessary.

Python packages

A separate xndpy repository will contain the necessary code for building packages. The actual build will utilize CMake, the packaging routines will be handled by a custom backend, flit and pyproject.toml. Developers will never need this, see above.

[skrah]

Done. The new repositories are:

https://github.com/xnd-project/xnd
https://github.com/xnd-project/xndpy

[skrah]

The issue is finished, but it will be left open and pinned so people can see what is going on.

[skrah]

It would be good to unpin libndtypes, libxnd and libgumath and pin xnd and xndpy instead. However, I no longer have owner privileges. @pearu, would it be possible to either restore my owner privileges or change the pins?

[skrah]

Ideally the proper history of all libraries should be restored, but merging all three turned out to be quite difficult. If this setup proves successful, it can be done later.

[pearu]

It would be good to unpin libndtypes, libxnd and libgumath and pin xnd and xndpy instead. However, I no longer have owner privileges. @pearu, would it be possible to either restore my owner privileges or change the pins?

@skrah, it nice to hear from you again! Yes, let me try to restore the privileges. Could you contact me via private email as I think I don't have your contacts?