86Box v4.0 released

This is the August 2023 update to 86Box, bringing many improvements, bugfixes (especially for non-Windows users) and some new hardware.

Mouse and keyboard support has been completely reworked, and should perform much, much better on all platforms, while also fixing a slew of bugs. Support for the ATI Mach8/32 was added, which is a first for the world of emulation, and VDE networking has been implemented as well (but not on Windows yet).