Only import better ranks

[Not-A-Normal-Robot]

What feature do you want to suggest to the game?

Importing ranks should only overwrite lower ranks. Example:

	Mode A rank	Mode B rank
Platform A	U	S
Platform B	A	X

Currently, if you export and import the savefiles from Platform A to Platform B, you're gonna lose your higher Mode B rank, and vice versa.

What should happen is that only the higher ranks get copied and the lower rank gets ignored so you don't have to play some modes again.

[MrZ626]

I think it *should* be "import your saving", not "update saving"