`ice.log` now includes DEBUG logs by default.
Remove unused option from config.txt
Adds pysteam as dependency, removes steam_user_manager
Removes steam_installation_location_manager

It's functionality comes for free in pysteam (as part of the Steam class)
Moves user configuration into its own object
Moves GridImageManager functionality into IceROMManager
Moves single method in process_helper to utils
Removes SteamShortcutManager (now uses pysteam)
Removes steam_grid (replace with equivalent pysteam functionality)