Implemented command line config overrides

You can set the file to read as the config file via the command line, like
this, assuming the program supports it:

  prog -config=file.cfg

You can also override indevidual key-value pairs in the config system
using this syntax:

  prog -Ckey=value

Both commands can be used together, and you can override multiple
key-value pairs at once. To use this feature of the ConfigUtility, it must
receive argc and argv as parameters to the Load() method.

todo.txt

@@ -1,6 +1,3 @@
-TODO: Config switch for the debug output
-TODO: A better way of handling the disconnection message
-TODO: LobbyMenu::HandleJoinRejection()
 TODO: Get the rooms working, even if only via hotkeys
 TODO: Fix shoddy movement
 TODO: Move the statistics into their own SQL table, instead of duplicating the structure a dozen times