Exposed PresentInterval on SwapChainRenderTarget so that VSync can be disabled if desired.
Removed the setting of MaximumFrameLatency from SwapChainRenderTarget, since this could override the setting from the GraphicsDevice.
Merge branch 'DirectX11VsyncDisable' of https://github.com/SickheadGames/MonoGame into DirectX11VsyncDisable
Added GetFrameLatency extension to PresentInterval.
GraphicsDevice now uses this extention.
Slightly clarified documentation.
Changed SwapChainRenderTarget to use new PresentInterval extention.