[Enhancement] Add game.libretro.XXX settings to in-game OSD

[zach-morris]

It would be beneficial to add a row item to the in-game OSD to quickly bring up the current game.libretro.core settings

As an example:
In DOSBOX, for Win3.1 games, I needed to change the settings for game.libretro.dosbox dosbox_machine_type to svga_s3 (not the default), and for other DOS games I had to set it back to vgaonly.

In the current implementation, I would have to go into Addons>My Addons>Game Addons>Emulators>DOSBOX>Settings to change that. It would be much easier if I could access the settings after the core is started. Note that a reboot / restart of the core might be needed after some of the settings are changed.

Adding a link to the core settings from the in-game OSD would be akin to Retroarches "Quick Menu" settings.

[garbear]

I've been meaning to do this. Thanks for jogging my memory.

[zach-morris]

Appears to be added and working great, at least as of version

18.0-ALPHA3 Git:20180722-23cbb1a41f