Snes9x 1.62

Another release containing a bunch of small things. There are a few game fixes and some UI tweaks, as well as some reorganization in the backend. The biggest front-facing feature is a Vulkan output for the Windows and Gtk ports. Like OpenGL, Vulkan can use the slang shaders in the libretro repository.

Snes9x 1.62
- Fixed SA1 division with negative dividend again. (Atari2)
- Fixed timing on several instructions. (pi1541)
- MSU1 audio with no loop point will not repeat from start.
- Modernized some old memory-related code.
- Fixed a desynchronization in interlaced modes and reporting.
- Remove SA1 access to WRAM.
- Added second set of registers between S-DSP and S-SMP. Fixes
  PAL version of Virtual Bart.

Gtk + Windows:
- Added a Vulkan graphics output method. Similar to OpenGL, this
  can use libretro's slang shaders.
- Changed the automatic frame skip throttle to take place immediately
  before showing the frame, making VRR work better.
- Add menu item to clear recent files entries.
- Add fixed window size changes up to 10x.

Windows:
- Improved the shader parameters dialog with sliders and resize.
- Allow disabling adding registry entries. Deletes any existing
  entries when the option is disabled.

Gtk:
- Switched to CMake for build system. Removed meson.
- Fixed some keys not working with modifiers. (Gutawer)
- Removed graphics options most people won't understand or need.
- Improved wayland support. Handle fractional DPI properly.