Substantially re-written in light of the May 22nd firmware, which had a `bisrv.asd` of the same length as the May 15th firmware, but different in operation - the byte order in `KeyMapInfo.kmp` has been flipped for SNES and Genesis. As there's no way to tell from just looking at a `KeyMapInfo.kmp` what the byte order should be, users must now provide both `bisrv.asd` AND `KeyMapInfo.kmp` files - the `bisrv.asd` is now hash-checked against known versions, and that's used to inform which byte order to use for the `KeyMapInfo.kmp`
Updated to support the new May 15th firmware. Also took the opportunity to make a few tweaks, including presenting the button tables in a more standard "ABXYLR" order, regardless of the byte-order in the actual SF2000 data files
Seems like there may be some more significant changes to the data format for the button mappings; I haven't had time to dive into the details yet, so just updating the tool to indicate it knows about the new firmware, but doesn't support it yet
