RMG Release v0.5.9

Rosalie's Mupen GUI

Fix parallel-rsp regression introduced in v0.5.8 (see libretro/parallel-rsp#12)
Fix corruption when using GLideN64 and resizing the window (see gonetz/GLideN64#2835)
Fix changing save state slot always selecting slot 0 on some system configurations
Fix changing speed factor always using 0% on some system configurations
Add color settings for the OSD in the settings dialog
Add 'Test Rumble' button to the options dialog in RMG-Input
Add 'Play Game with State' to the context menu of the ROM browser
Add '--load-state-slot' commandline option
Update cheats and GLideN64