Fixed compile warning, thanks to Michael Pohoreski

Better fix for bug 2207 - SDL_RenderSetViewport behavior is different/incorrect on OpenGL renderer vs DirectX renderer
At least, it works better here on my Mac. :)

Added viewport test, contributed by Andreas Schiffler and improved by me and Ryan Gordon.
If it works correctly you should see a square moving from the upper left to the lower right, with a little yellow box at the top of the moving square.

You can pass --target as a command line option to have it use a render target instead of rendering directly to the screen. The output should be identical in this case.

Added space in the common state structure for render targets

Fix viewport being upside down in OpenGL renderer.

Fixes Bugzilla #2207.

Mac OS X 10.9 no longer uses the -psn_XXX command line arg for Finder launches.

Fixed bug 2240 - On OS/X after calling SDL_SetWindowBordered right mouse clicks no longer register

philhassey

On OS/X after calling SDL_SetWindowBordered right mouse clicks no longer register.

Steps to Reproduce:

1. Open a windowed window on OS/X. (With the border on.)

2. e.button.button will give values 1,2,3 depending on which mouse button I click.

3. Call SDL_SetWindowBordered to disable the border.

4. e.button.button will only give values 1,2. 3 (right mouse button) stops coming through.

Expected result:

I expect all mouse buttons to register.

Backed out changeset e8f93c2ebda3 - it didn't actually do anything useful

Turning --no-undefined back on, to see what platforms are still broken.

Fixed comment typo.