- Removed now obsolete incompatibilty warning for 0.1.3 -> 0.2.0.

* Simplify project files
* alire.toml: release set external for build mode
Default is already in the project file.

* alire.toml: fix build mode external name
Co-authored-by: Fabien Chouteau <chouteau@adacore.com>

Compilation issue should be fixed now.

Compilation of the unit hangs with GNAT FSF 8.

Using `for Prefixes'Size use Integer'Size;` instead of `with Size =>` aspects fixes the problem.

* Migrate to ada-actions.

* Formatted to 80 characters line width.