Field Read and Write Overloading for Prefereneces

[saturn-volv]

This adds an abstracted PreferenceMap, which behaves as a StringMap but with some field read and write overloading.

So now instead of needing to call:

Save.instance.options.downscroll = true;

You can accomplish the same thing with:

Preferences.get().downscroll = true;

There are other use cases for this but I'm tired and cannot bring myself to list them all right now

[saturn-volv]

return get().value = value;

I initially did but the code style doesn't want inner assignment used.

[Raltyro]

i forgot codestyle exists whoopsm..

[EliteMasterEric]

This looks like a great bit of code cleanup!

Also, the codestyle is bugged, it should be allowing inner assignment in return statements.

[EliteMasterEric]

I just looked into this more and I actually don't think this is much of an improvement over the existing Preferences map.