The main OpenTTD directories can be found in various locations, depending on
your operating system:
	1. The current working directory (from where you started OpenTTD)
		For non-Windows operating systems OpenTTD will not scan for files in this
		directory if it is your personal directory, i.e. '~/', or when it is the
		root directory, i.e. '/'.
	2. Your personal directory
		Windows: C:\My Documents\OpenTTD (95, 98, ME)
		         C:\Documents and Settings\<username>\My Documents\OpenTTD (2000, XP)
		         C:\Users\<username>\Documents\OpenTTD (Vista, 7)
		Mac OSX: ~/Documents/OpenTTD
		Linux:   $XDG_DATA_HOME/openttd which is usually ~/.local/share/openttd when
		         built with XDG base directory support, otherwise ~/.openttd
	3. The shared directory
		Windows: C:\Documents and Settings\All Users\Shared Documents\OpenTTD (2000, XP)
		         C:\Users\Public\Documents\OpenTTD (Vista, 7)
		Mac OSX: /Library/Application Support/OpenTTD
		Linux:   not available
	4. The binary directory (where the OpenTTD executable is)
		Windows: C:\Program Files\OpenTTD
		Linux:   /usr/games
	5. The installation directory (Linux only)
		Linux:   /usr/share/games/openttd
	6. The application bundle (Mac OSX only)
		It includes the OpenTTD files (grf+lng) and it will work as long as they
		are not touched