Allow changing refresh-rate provided to games (50/60Hz)

[emoose]

Some games where the framerate is tied with game-speed, eg. MGS2/MGS3, may have support for 50Hz when VdQueryVideoMode returns a 50Hz refresh rate, in MGS2/MGS3 case it seems to adjust the speed of a bunch of different things when 50Hz is returned.

If we had a setting that could allow switching between 50/60 it could help some users that can't always maintain a constant 60FPS (such as myself ;_;), since 50FPS is of course easier to achieve than 60.

For the setting to work properly it'd also need some way of limiting the games FPS too though, as I think VSync would still only work at the monitors 60Hz rate, using an external limiter like nVidia control panel to limit it to 50FPS seems to work great, but something built-in would be more preferable.

[krittinen]

Adding a framerate cap that's unrelated to VSync would be good, some games such as Sonic Unleashed handle unlocked framerates well for the most part.