[Ohrrpgce] SVN: teeemcee/7738 Fix non-320*200 games not being recentered properly, and Game not recent

[subversion at HamsterRepublic.com]

teeemcee
2016-02-28 06:30:09 -0800 (Sun, 28 Feb 2016)
375
Fix non-320*200 games not being recentered properly, and Game not recentering after quitting them.

When launching a very small game, the entire window would end up off the top-left
of the screen!

I made gfx_sdl handle recentering itself when set_scale_factor is called.
But it seems when resolution changes it depends on the context whether the
window should be recentered.
---
U   wip/allmodex.bas
U   wip/game.bas
U   wip/gfx_sdl.bas
U   wip/yetmore2.bas