src: remove check_init_instance everywhere

Signed-off-by: Jean Privat <jean@pryen.org>
tests: update related to the removal of check_init_instance

Signed-off-by: Jean Privat <jean@pryen.org>
Merge branch 'kill_newcheck'

Remove runtime checks on uninitialized attributes at the end of object
constructions.
Thus, uninitialized attributes will now fail (abort) on the first read
access.

Some people [citation needed] find that the current specification force
the usage of `nullable` on attributes that should not be null in
practice but that cannot be not nullable because the initialization is
not done in the constructor.

Some other people [bis] also state that the current check is problematic
with potential exception/longjump since uninitialized object could still
escape.

Therefore, because the next big devel planned is the constructors, I
prefer to solve this specification point before. This pull request is a
RFC on the new spec (and/or implementation).
SDL : Comments fixed and added in SDLDisplay class

signed-off-by: Geoffrey Hecht  <geoffrey.hecht@gmail.com>
SDL : Comments fixed and added in SDLDrawable class

signed-off-by: Geoffrey Hecht  <geoffrey.hecht@gmail.com>
SDL : Comments fixed and added in SDLImage class

signed-off-by: Geoffrey Hecht  <geoffrey.hecht@gmail.com>
SDL : Comments fixed and added in SDLRectangle class

signed-off-by: Geoffrey Hecht  <geoffrey.hecht@gmail.com>
SDL : Comments  added for SDLMouseEvent, MouseButtonEvent,MouseMotionEvent  class

signed-off-by: Geoffrey Hecht  <geoffrey.hecht@gmail.com>
SDL : Comments  added for SDLkeyEvent  class

signed-off-by: Geoffrey Hecht  <geoffrey.hecht@gmail.com>
SDL : Comments  added for SDLFont  class and methods

signed-off-by: Geoffrey Hecht  <geoffrey.hecht@gmail.com>
Merge branch 'patch-sdl'