Now we can call functions that need to access GPU resources explicitly
on the draw thread.

Controller::WasKeyReleasedThisFrame() is now keyboard->key_released() so
there is usually no need for a controller. They will completely disappear
when joystick axis binding has been ported to InputDevice.

The scene now owns its renderer, so there is no need to keep a list
of existing renderers and to call Renderer::Get().

This was not a very smart class. We replace it with a bidirectional map.

We used to have lol::map::empty() to empty maps, but in std::map
this method is called clear(). It sounds safe to harmonise between
our types and have lol::array::clear() too.

Seems to still build in lol, will check other works to be sure

Added macros to help basic setup

getter default params are better now

Next pass is clean-up and fix of all the old usage

Will resume on other computer.