Log Message:
PC6001VX: update to 3.1.0.

pkgsrc changes:

* make debug monitor, ffmpeg4 for video capture, and SDL2 for joystick
  support optional (for low performance machines; enabled by default)
* fix a URL for online help (already fixed in upstream)

Upstream changelog:

 * Better virtual keyboard display size.
 * Virtual Keyboard is now mouse operable.
 * Assigned "reset emulation speed" to middle mouse button.
 * Added "Convert replay to movie" menu.
 * Now audio is muted during encoding movie.