ControllerConfigDiag: Potentially fix scaling problems on high DPI

Fixes issue 7940 hopefully.
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
Externals: update libusb to version 1.0.19
Externals: add Dolphin-specific patches to libusb
Externals: add hidapi 0.8.0-rc1
Externals: steal & modify hidapi.vcxproj from Armada
WiimoteReal: reimplement using HIDAPI

Using the HIDAPI library has the advantage that we get Wiimote and
DolphinBar support on all platforms with only one IO implementation.