Refactoring louloulibs and cmake

Use OBJECT libraries
Remove the louloulibs directory
Write FOUND variables in the cache

Little scopeguard cleanup, and add a test

Very little optimization by using a simpler scope_guard when possible

The version with the vector, that can be disabled etc, is “very” slow, so we
use unique_ptr when we don’t need to disable it, and when it only contains
one function

Replace all include guards by #pragma once

It’s $CURRENT_YEAR

Style fix

Move all constructors at the top of classes

louloulibs is directly included, instead of being a submodule

Because this is a nightmare to manage