ControllerConfigDiag: Potentially fix scaling problems on high DPI

Fixes issue 7940 hopefully.
VideoCommon: Make GPU syncing hack optional

This hack is there for quite a long time, and lots of games crashes if it's disabled.
But it's still a hack, so it shouldn't be enabled hard coded. This commit create a new
ini option for this hack which is enabled by default.
Maybe some games does still run very fine without this hack.
GeometryShaderManager: Set viewport in SetConstants().

Setting it in the callback is too early.
Merge pull request #1771 from Armada651/geom-viewport

GeometryShaderManager: Set viewport in SetConstants().
Merge pull request #1745 from degasus/remove_gpu_sync

VideoCommon: Make GPU syncing hack optional
Tools: buildbot try with binary diffs
Merge pull request #1774 from Tilka/binary_try

Tools: buildbot try with binary diffs
PixelShaderCache: Don't use GetDimensions() for the sample count.

This function is bugged on Windows 7, and statically declaring the sample count is trivial anyway.
Merge pull request #1769 from Armada651/msaa-samples

PixelShaderCache: Don't use GetDimensions() for the sample count.
Merge pull request #1718 from lioncash/wxdoesitagain

ControllerConfigDiag: Potentially fix scaling problems on high DPI