The other subfolders of tools/ had already been moved to either
editor/, misc/ or thirdparty/, so the hiding the editor code that
deep was no longer meaningful.
The new Quick Filter Files behaviour since 8b47e26 had not been implemented,
so this implements it and makes it an editor hotkey instead of a menu entry.
Fixes#7582.
Made sure files in core/ and tools/ have a proper Godot license header
when written by us. Also renamed aabb.{cpp,h} and object_type_db.{cpp,h}
to rect3.{cpp,h} and class_db.{cpp,h} respectively.
Also added a proper header to core/io/base64.{c,h} after clarifying
the licensing with the original author (public domain).
That year should bring the long-awaited OpenGL ES 3.0 compatible renderer
with state-of-the-art rendering techniques tuned to work as low as middle
end handheld devices - without compromising with the possibilities given
for higher end desktop games of course. Great times ahead for the Godot
community and the gamers that will play our games!
