return 1 added after sam remark

Moved ImageLoader to ResourceLoader, so that loading is extensible.
i.e. here: Zed image loader now loads up a tileset instead of being a
hacked image loader.
Goal is to support more funky stuff (wad, pak .....)

imGui docking extension tweak
tileset new getters

Added scissor mode in renderer
Added scissor support in imGui
Mouse scroll sensivity tweak

small imgui extension
scene palette shader crashfix

sdl integration now supports OS character input as per existing in sdl.
Use SetTextInputActive to turn it off/on

......

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.

- removed 0 CR characters
 - removed 7 trailing whitespaces
 - replaced 332 tabs with spaces

- Most recent version is in with index buffer support

Shader replacement code for older shader version is now fixed

This will allow us to generate sounds on the fly on several dedicated
channels. Until now we could only play fully loaded samples.

We have no hope of extending lua_State to add more data to it, because
that object may be created by Lua itself, for instance within a coroutine,
and it has no knowledge of our version of the object.

This has proved unreliable because coroutines create whole new environments,
so one of the only ways to store user data and access it even from coroutines
is to use lua_setglobal().

This will help us deal with shader name collision. Breaks the Windows
build for the moment, unfortunately.

This allows actors to perform draw commands in TickDraw(), even
if it’s not exactly what we want in the future.