Smallish update - Total conversion mods fix — Amnesia: The Dark Descent Steam update #67884

Apparently something went wrong on the previous update, making it a bit difficult to run total conversion mods out of the box. Version 1.311 addresses that issue so you don't have to hack stuff to make them work. Changelist: - Launcher checks for the 'DefaultMainSettingsSDL2' entry in the init config file passed as argument and falls back to the game's default if not present. - Game checks for the 'DefaultMainSettingsSDL2' and 'DefaultUserKeysSDL2' entries in the init config file passed as argument and falls back to the game's default if not present. - Added "steam_appid.txt" file to make it possible to run the game exe outside Steam.