Adds info about what's going on during initialization.
Code cleanup (4).
Moves --motion-blur to config file and rewrites config initialization a bit.
Code cleanup (5).
Moves show_fog to globals.py + fixes a motion blur config bug.
Removes 'flat' from config and move to globals.
Moves show_fog to graphics + one suggestion.
Moves --show-gui to globals.py + SHOW_FOG  -> FOG_ENABLED.
Partially reverts of f10f4604ddabb4d9fb19b82a68ec63d3e01b4993.
height levels for ores, like in MC