Changed paths and name of header file in text of VisualC.html.
Fixed the logical size for rendering to texture, thanks to Mason Wheeler.

Mason Wheeler

The SDL_RenderGetLogicalSize function should always return the amount of pixels that are currently available for rendering to.  But after updating to the latest SDL2, I started getting crashes because it was returning (0,0) as the logical size!  After a bit of debugging, I tracked it down to the following code in SDL_SetRenderTarget:

    if (texture) {
        renderer->viewport.x = 0;
        renderer->viewport.y = 0;
        renderer->viewport.w = texture->w;
        renderer->viewport.h = texture->h;
        renderer->scale.x = 1.0f;
        renderer->scale.y = 1.0f;
        renderer->logical_w = 0;
        renderer->logical_h = 0;
    }

This is obviously wrong; 0 is never the correct value for a valid renderer.  Those last two lines should read:

        renderer->logical_w = texture->w;
        renderer->logical_h = texture->h;
add in alt+enter keyboard shortcut to test common to toggle fullscreen desktop
Added SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS to the documentation for the joystick and game controller APIs
Don't close already-closed audio devices during SDL_Quit().

Otherwise, we spam a bunch of unnecessary SDL_SetError() calls.

Fixes Bugzilla #1791.
Added a FIXME.
Strip newlines from messages in SDL_Log*() before calling logging function.
Don't crash if SDL_AudioQuit() is called twice in a row.

Fixes Bugzilla #1396.
Fixed some __BEOS__ vs __HAIKU__ preprocessor tests (thanks, Axel!).

Fixes Bugzilla #1773.
Don't set the same GL context twice on Mac OS X (thanks, Alex!).

Fixes Bugzilla #1939.
Patched to compile on pre-C99 compilers.