This commit introduces REUSE compliance by annotating all files
with SPDX information and placing the reused licences in the
LICENSES folder.
We additionally removed the docheader tool which is made obsolete
by this change.
The main LICENSE and copyright text of the project is now not under
my personal name anymore, and it belongs to "The Respect Project
Contributors" instead.
This change restores author names to several files, giving the
appropriate attribution for contributions.
I'm creating a workaround here, which is not exactly happy with, but
adding "uopz" as a dependency to run the tests make it harder for
developers, including myself.
-Rules\Each improvements and new tests, now can validate array keys too. Better exception reports for it.
-A very abrangent test including several cases on ValidatorTest
