Configuration files

Do not merge - this is a preliminary PR for discussion.

As of now, incorporates Dolphin's INI code for a configuration system. So far, handles for input controls have been added, but they haven't been hooked yet into the parts of code that use them. 
This class probably doesn't need to exist if you're using maps. You can have strings as the values of a section's map and let the caller parse the string how they like. You could include the parsing code you have here in some utility class etc so that everyone can use it if desired.