Making use of the newly added `buildRomData()` method.

Handling of GameShark RAM banks differently.
Added parsing integer value errors.

This has been moved to emukit.

Uses js-sys to interact with the Javascript VM, to obtain Date() reference.

Makes use of the most recent save state support in EmuKit.
Thumbnail image support.

Added more flexible way of computing those paths and made them save into the ROM directory.

Using static methods instead of global functions.