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

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

The containers no longer force the user to use the ptrdiff_t type for
size information. For convenience, size() now always returns an int,
and the size_s() method offers a way to handle arrays with more than
2 billion elements. Internally, we still use ptrdiff_t, though.

Since so much code had to be changed, I took the opportunity to get
rid of capitalised accessors for classes that are lowercase.

MeshViewer first pass

Big FAT pass on windows-warning. It is better now.

Constants : Added minus one.

core: calling InitGame() at the first tick of an entity. InitDraw is still uncalled yet
fixed mrpigeon and orbital accordingly

disabled until the engine code itself is ported to SDL2.

- fixed 1270 CR characters
 - fixed 56 trailing spaces
 - fixed 5085 tabs

Useage :
- Link action to key :
Input::LinkActionToKey(ACTION_TYPE Action, struct Key Button);
Input::UnlinkAction(ACTION_TYPE Action);
- Query action directly :
Input::GetStatus(ACTION_TYPE Action);
Input::WasPressed(ACTION_TYPE Action);
Input::WasReleased(ACTION_TYPE Action);

Also works with raw button, but not advised :
Input::GetStatus(Key Button);
Input::WasPressed(Key Button);
Input::WasReleased(Key Button);

Added Escape button in to quit Orbital.
Added Camera control with some little damping sweetness in Camera logic in main Tick.
First Commit \o/