Avoid SDL display bounds dependency

[acmlira]

Avoid SDL display bounds dependency

The functions of SDL had issues in distros like Ångström:

SDL_GetDisplayBounds();

and

SDL_GetDisplayUsableBounds();

and

SDL_CreateRenderer();

they depended on some certain workaround to run correctly on any systems. They were useful to get the size of the screens.

Plus

We now introduce 3 environment variables for execution. Since we do not have an automatic viewport they need to be set up they are:

	TC_WIDTH	TC_HEIGHT	TC_FULLSCREEN
Description	Size of width in pixels	Size of height in pixels	Is fullscreen or not
Values	int	int	bool

In case the standard resolution is not met, it will be 640x400. That should change soon.

Pull request

I think that squash should not be done since each commit is semantically and syntaxically correct.

[otavio]

So nice! @acmlira good work in splitting the commits! So easier to review!