New menu system

[thelusiv]

Alright to pick up where I left off, I have started creating an OPTION template class which will store a generic option and its list of values etc. The SETTINGS class will manage it (it's in settings.h) by maintaining vectors of each type of option (it already maintains vectors something like this but simpler).

This will greatly simplify menu design because now each widget that represents an option in the menu needs only to know the name of the setting that it corresponds to (in fact, they already do). Then using the setting name it can look up the data necessary.

The options data will be loaded when the SETTINGS class gets initialized and all dynamically generated value lists (like list of cars, car paint, tracks, and available resolutions) will be generated then too. The options definitions will be read from a file in the configfile format we use for other files, stored in "data/settings/options.config".

Since this file will have all the default values for each option, as well as the name and category, this data could be used to generate a VDrift.config with default values (which means we could perhaps get rid of the file "data/settings/VDrift.config"...)